So I'm a teen and am starting a new school next year. I get a 12 week break so would really like to try and get in shape, mainly to boost self confidence. What types of exercise / diet would people recommend?

I don't think I'd ever get skinny but I'd I could swap out some fat for muscle that would be fantastic!

Hey folks, so I've worked nights for the last two years and it sucked. flat out sucked. I would average 4-5 hours of sleep before and after a shift and now I've moved to afternoons (3pm-10pm) I find my body still thinks 5ish hours is great.
Often I wake in the middle of the night and then that's it. I'm up. it truly sucks. anyone got advice on how I can change this? I've been on afternoons for a little over a month now, so could it be more I'm still adjusting? appreciate any help and advice.

edit ** thank you all for the advice. I will have to work out a routine and make sure to sick to it, then just not get too down when only making small steps.