I don't get my champion when I level up?

I made a new account so I could play with friends. But every time I level up, I get three choices of champs to choose from. But when I choose a champion, it doesn't show up in my champ collections? Earlier today I chose from Illaoi, Syndra and Garen and I chose Illaoi and she wasn't unlocked. This happened twice on another one when i chose Vayne and she wasn't unlocked.

Did I forget something or is this a problem?