Need some champ idea's.

Since you are so new to the game, you might not quite understand what other champions are like yet. I suggest you spent your ip on cheaper champions that represent that specific group of champions. Suggestions include garen for top, annie mid, and sivir / ashe adc. Until you decide a role that you like best I suggest against buying a 6300 champion unless youve tried the champion in free week and really like him. If you like yi I suggest aatrox or kayle

 

I play Yi in ranked. He's abit rough and you have to be careful with him. But if you Rush Wriggles->Youmuus you can sneak dragons early and if you ever get a kill or two you can snowball extremely quickly.