Bug

For some reason when i level up it doesnt give me any new spells. How do i fix that?

You need to buy them from your class trainer

You probably played retail, WOTLK and the other expansions pre - MoP (not quite sure if you had to learn spells in Cata, I forgot) you have to go to your specific class trainers, and learn the spells you unlock by levelling, they won't automatically show up in your Spellbook. Also there are multiple Ranks in spells each one being stronger then the previous rank. + There are some class specific quests for certain skills you need to complete to unlock the skills. Pretty fun to be honest, you gotta work for it.

Kind regards,
Data.