Finding Your Main
1. Looks are everything. When selecting a Main, be sure the one you choose has a presence that is almost intolerable to your opponent. A hideous Wario who wins is a good looking Wario. A pretty Marth who loses is quite ugly to witness.
2. A copycat is a smartycat. Search online of the characters you think you would like to main. Watch videos and learn tactics you were like you recreate in your own experience when playing. When you see things that make you go "Ooh, that was good. I wanna do that", then practice those. When you like what you've done, continue on with more matches until it becomes as natural as breathing to you. From the newfound experienced moves you've learned, you are now able to fully add your own flavor to the mix that you can call your own. If it feels good enough to main, it is good enough as the main dish (lamest ****ing pun I eve-).
3. Sky's the limit? Oh how convenient, quote originator, because sky's the blast zone. Build your personality into your main, and don't rush to what's on paper as to who's good in what areas. Feel great with who you are playing as by not seeing the fighting element first, but as a platformer/acrobat, even if you're Ganondorf. Timing, patience and landing moves are crucial to your success or you bite the dust. There is no popularity contest. You just naturally become your own trademark when you put in the time.
Good Luck!