Any tips for Barcelona and Lisbon in June/July?

Hey Tildes,

My husband and I are planning a trip to Barcelona and Lisbon at end of June.

I'm looking for any tips and things to know about Spain/Portugal.

Any thing I should get in advance like museum tickets or tours. Looking for a night life scene that isn't so much of a tourist trap. Also, any ettiquete I should know about. This would my second time in Europe, so any advice would be appreciated.