i went to ellinia and to Grendel and left clicked on him and he says it looks like you read all the books?

At the start for the training, did you click on another job with Mai?

I found if I picked warrior with her, I couldn't become a magician after if I changed my mind... the quest wasn't registering at level 8.
I just deleted and restarted the character.

you dont have to delete, just go to the job adv. and say you want to pick another class