I'm considering on becoming a first-time dog owner soon, looking for advice

Some advice: the size of the dog and the amount of attention, exercise, etc, are poorly correlated. A greyhound is a fairly large dog, but they need a very small amount of vigorous exercise each day, and spend most of the rest asleep or lazing around. By comparison a Jack Russel Terrier is a small dog but is an endless font of energy. (Terriers in general need a lot of exercise to be happy.) So make sure that you're getting a breed of dog that really does match your lifestyle.

Also, be clear that you're getting a roommate that'll be with you for 10-20 years. While in choosing a breed you'll have some sense of what kind of roommate he or she will be, they'll be a person that you have to coordinate your life with in a way that cats just aren't. Think of a dog like a toddler. They have opinions about the world, and you'll need to work with them.

In that they're a person, you really will need classes to teach them how to behave and to teach you how to guide them through life. For all that I talk of them like people, they aren't humans and you need to understand dog psychology to be able to work with them well. Everyone will be happier if both of you take classes together.

@MimicSquid had some good points. I’ll add the following:

• Do you have a dog park (or an apartment common area) close by? This could help with the lack of a yard. Keep in mind, however, that not all dogs are dog park dogs. They are often a chaotic environment for dogs to deal with, and some just don’t like it.

• Training and socialization are VERY important. I cannot emphasize this enough. Many people skimp or skip them, especially with small dogs, and the results are not good.

• What is your routine? If you are single and out of the house for eight hours a day for work, you will need to hire a dog sitter. If you like to take a lot of vacations, dog ownership can be limiting.

• Get a good harness. When my mom worked at a shelter and a vet, dogs often came in with neck injuries due to people yanking and pulling too hard on their neck.

• Some dog breeds are off-limits. Bully breeds, many herding breeds, among others, require experienced people to handle, train, and socialize them.

• What are the apartment rules? Also consider dog breeds that aren’t loud (e.g., no beagles).

• Finally, you might consider fostering a dog before permanently adopting. You can help a shelter dog, and see whether or not having a dog is good for you without a full commitment.

Lots of good advice here already, and I'll second the /r/dogs recommendation.

Here's some additional stuff that I haven't seen mentioned:

A lot of common dog advice is based on outdated and potentially damaging concepts of dominance. Be skeptical of anything that talks about being the "alpha". There is a big difference between being authoritative and being autocratic with your dog, and there is a lot of bad advice that will push you towards the latter.

Patricia McConnell's The Other End of the Leash is a fantastic read. More of a "human training" book than a "dog training" book, it helps put our own actions as people into the context of dogs' psychology, so that we can better understand how our dogs interpret us and change our behaviors accordingly.

Dogs are responsibility. In choosing to get one, you are committing to meeting the dog's needs, even if they're difficult, frustrating, or costly. A lot of people neglect this consideration and make their affinity for their dog conditional -- based only on their ideal of what a dog should be rather than who their dog actually is. No matter what dog you get, it is fundamentally an animal that is entirely dependent on you for attention, care, survival, and socialization. These are things that have to always be accounted for.

The aforementioned responsibility fundamentally changes a lot of things about how you experience the world. Time away from home will now be measured in "dog time", and you'll be aware of how much you're away and how long it has been since your dog has been out. For example, prior to dog ownership, a social night out might have some immediacy and spontaneity to it, where you can keep the night rolling if you're having a good time. With a dog, however, you've got to either plan for care in advance or keep to a schedule for returning.

Solo dog ownership can be hard, as there's no good way to split responsibility. For a lot of people, work plus commute means that the dog would be alone, unable to go out, and potentially crated for ~10 hours consecutively, which is too much. It's hard to stomach, but sometimes getting a dog isn't the right call for an owner simply because the owner cannot rearrange their life enough to meet the dog's needs.

Another tough thing to think about, especially for someone in the beginning stages of considering dog ownership, is worst case scenarios. Should you become incapacitated, who will care for the dog? Being the sole provider for your dog means that you are also a single point of failure. Make arrangements to guard against that. Make sure someone has a key to your apartment and would be notified in the event of an emergency. Make sure someone you know would be prepared to take the dog on long-term should something happen to you. It's not likely, but it's not something your dog can afford you to leave unconsidered.

Dogs are love. Part of what eases all of the above responsibilities and difficulties is that a dog's companionship can bring a richness to our lives that is unmatched. Ideally, you won't have to worry about all of the troubles of caring for your dog because you'll love your dog so much (and they'll love you so much) that the bumps and troubles aren't just worth it, but you'll genuinely want to do them. My dog brings comfort, joy, and delight to every single day of my life, and I make sure to repay him in kind. We are genuinely better because we have one another, and my love for him makes any of the difficulties or frustrations of dog ownership fall away.

I would research breeds, especially for those with known congenital defects or high-rates of physical problems

Many breeds where humans have strayed too far from natural proportions might be visually appealing but are very likely to suffer, e.g. certain German shepherd breeds where the back legs are a very different length to the front legs leading to back problems, Dachsunds and corgis are also notorious for having hip and back problems, breeds with smushed faces can suffer breathing difficulty

Getting a breed that has been programmed for a certain work function that has nothing to do with how you'll be living your life is also not super great for either of you, e.g. various cattle dogs and shepherd breeds when you don't intend to have them herding sheep/cattle, various sniffer-dog breeds like Beagles if you dislike the idea of them turning a 10 minute walk into 1 hour because they have to inspect everything

Do go for dogs that are friendly around humans, dogs, and even cats if you can find such an animal (I personally know 2x cats that were horribly attacked by dogs, so let's avoid putting more of that out there)

And for apartment living, you're definitely going to want a dog that is easy to house-train or is already house-trained

We have a Beagle-cross (one-quarter husky), love him to bits, and he's fine in our apartment as long as we walk him and play with him every day

If you're not interested in a puppy, I would highly suggest looking for an older dog (5 years or older). Shelters have a hard time getting older dogs adopted out and usually have a lot of them.

Older dogs can be already trained and have already developed their personality so you can get a good idea for what type of dog they are much faster than with a puppy.

Make a fund for emergencies and look into some kind of health insurance. If your dog has a health issue, it can become a financial liability. And you'll want the best for your buddy.

Look into dog training. It is much easier to train than to correct.

Try getting a dog that does not shed. I love my little buddie but there's fur in my food. Not fun.

In any case, you will have a blast :)

There are quite a few large breed dogs that are suited for apartment life. The caveat being that many apartments have weight limits, so finding a new apartment could be difficult if you needed to move for any reason.

A low energy breed does not mean that they cannot be moderately active. My dog for example is considered low energy and can oftentimes seem comatose, but she's always up for a walk, a hike, a cuddle, or a ride in the car. She just doesn't demand it (generally). She does have times where she's energetic (gets the zoomies, super excited about meeting people, etc.) and if someone were to only see her then they would never realize that most of her time is spent passed out.

Many breeds have temperaments that are associated with them, but that's not a guarantee that you'll get that temperament. I like the idea higher up in the conversation that suggested fostering for that reason.

As a non-dog owner, I’ll just say to follow the rules for your new pet in public spaces. I live directly across the street from a park where dogs must be leashed at all times. There are a handful of neighbors who ignore this rule and treat the space like a dog park.

You just never know how someone else’s pet will react to your young children (or your own pet) nearby, and since I don’t have a pet of my own, my 3-year-old isn’t used to having dogs run up to him to say hello even if the pup is perfectly friendly. For me, your leash helps avoid the situation of scaring an unsuspecting child who doesn’t interact with animals a lot.

All that to say, I love a respectful dog owner! Making this thread shows that you are on the path to being one.