I am wondering how to put my virtual pro which I made and I really want to practice with him.
Simple answer: you can't
Ever since FIFA 13 (I think), you have not been able to practice with your pro in the arena. This happened when EA decided to separate the offline and online virtual pros as people were playing offline with friends and boosting.
The only real way to "practice" is to play games with your pro.
Online: either Drop-In matches or Pro Clubs games.
Offline: progressing through your career
Just take a photo of it and recreate in create player.
watch this video!! I don't know if it will work for fifa 15. But it works for 16 and 17.