Bolt, I just want to warn you.
If you play Garen, you're probably gonna get some backlash for it. The last season update for the game made Garen annoyingly strong and tough. I'm not saying you shouldn't play Garen, he's an excellent starter champion, but people might hate on you for it.
The good news, you will almost NEVER meet these people ever again, so they can't do much more than hate on you during a match.
Also, it wouldn't be a bad idea for spend at least 5 bucks or euros or whatever currency you have on some RP (Riot points) points, they have a lot of cheap skins for the characters that average about 250 RP but they won't be up forever.