I'm trying to become a better player, I really want to reach Gold League at the least. I have a problem though. I'm in bronze right now and the last 4 games I was in had at least one player afk and leaving us at a disadvantage from about 10 minutes on. What can I do next time to stop this?

If someone goes afk during your game there honestly isn't much you can do about it outside of reporting them at the end of the game. Just hope for the best. While going 4v5 isn't fantastic it doesn't mean its an automatic loss on your end.