I've already leveled a sorcerer up to 50 and I think my warrior is level 40, but I wanna play a new character, what should I make?
Totally up to you. If you like melee but want something fresh, then consider Concealment Operative. Very good singletarget spike damage, excellent utility (Toxic Screen removes *a lot* of bad stuff from you - including movement-imparing effects, DoTs and delayed blast explosives - like those that help pyros unload 15k burst on someone's arse). Healing is graet, especially in PvP environment due to being able to duck, rendering you immune to pulls and charges.
Fancy ranged - go Sniper. My favorite ranged class for PvP at this time. Mercenary is great for PvE DPS, and, despite of what whiners say, is perfectly playable in Pyro spec (has cleanses, which are amazing, can bust out of a critical derpsmashnoob's root with Degauss, tons and tons of instant cast-based damage which only requires timing to execute). Merc healer is also my favourite healer to play in both environments.