I am a level 17 SPriest but some of my friends are telling my to go Discipline. Which is better overall for both PVP/PVE? All opinions help!

It really just depends on what role you want to be. If you want to deal damage, shadow spec is veeeeeery good at this. If you're looking for a bit of versatility and want to be able to heal and do some damage, then I would go discipline. When it comes down to these types of choices it's best to ask yourself what YOU want to do, because in the end you're the one that's going to be playing this character, not them.

i personaly prefer shadow. if you know how to play them they are pwn