struggling to start on this game. Whos the best character to play?

I've been playing Singed since Season 1... he's the most fun even when you're losing, because you fight by running away.

It's also easier to farm minions with his poison until you master last hitting (because he's made to push so you don't need to worry about freezing the lane)

Support is also a good way to learn, try Yuumi, as she rides another champion, so you don't need to farm or move, giving you the chance to practice abilities and map awareness.

ARAM is a good way to not get yelled at as much and learn many champions quickly.