You don't always expect a sequel to a teen movie - at least I didn't in this case to be honest. But obviously there was more to tell - there was more to explore with the characters from the first movie. It feels like this can stand on its own, but it never hurts to have seen the previous movie to maybe enjoy certain character moments even more.
That all being said, we get introduced to new characters as well. There is still teen anxiety (although I reckon the actors themselves are even further removed from the age the characters are supposed to be - shouldn't be too much of an issue while watching though). Age ain't nothing but a number? No pun intended and no I am not trying to connect this with a song.
If you can suspend your disbelief and are ready to go on a summer journey with some likeable but obviously flawed and not yet fully grown characters ... you could do worse. Take the issue with skin one of the characters has - very relatable, even if you never had the issue. You really feel for her.