Junctioning problem and magic

[Varti]

Hello all my name is Andrei and i started playing FF8 3days ago. Now i am arround lvl 19 with Squall and 14 15 with the rest of characters.

I am at the final of the 2nd cd but i have big problems at defeating cerberus and edea. I read the guide and there is something there about junctioning magic elem-j atack def. but i don`t know how to use them.

I also heard that you can refine magic but i don`t know how. Thank you for understanding me and pls help me