I found the first storyline to be deeply uninteresting and I never got around to the third one but, as most people have already pointed out, the middle story was really entertaining and holds up in all my rewatches. It includes classy romcom tropes like childhood friends, neighbors, frenemies, fake dating but it manages to pull them off believably and make a sweet story out of them.
I think I might give the third story a chance at some point but all in all I definitely recommend this if you want a light-hearted and refreshing drama about teens!