what you should also do is when playing your friend, instead of playing to win, play to try and see what you can pick up from them, such as tactics, habits or other decisions they make in game. basically try to figure out their style. read them. that is how you play melee. it is like a puzzle game. in general, top level melee is trying to figure out what each person is doing and finding a way to punish what they are doing, either by reaction or read, and using their character's tools to do just that. when you can pick up what your opponent does, youve learned melee, and can basically beat them with almost any character, so long as you know how to punish their decisions.
every little decision in melee counts, and learning what you can do in which situation and knowing all details as quickly as possible, you can probably kick some ass.