I'm trying to decide on a power set to pick for my main, right now I'm playing a celestial just to get a hang of the game, it might/might not be my main.

In past games I've usually played casters and healers:
WoW- Mage (range dps) and Druid (HoT's and heals[didn't spec dps])

WAR- Magus (range dps, mostly dots), Archmage/Shaman (heals, mix of direct and HoTs), Squig Herder (range damage with pet)

EQ2- Wizard (range damage), Warden (HoTs and some melee), Defiler (wards [damage absorbtion] and heals)

Based on past mmo experiences I assumed that the celestial would be a standard priest and would have a hard time doing damage, but it seems to be going fine, is there a different power set that might suit me a bit better?

You're obviously into a ranged theme so any power set except MA and Might/ TK blades will suit you. I recommend creating your own character concept and then choose powers to fit that concept. Get in the game, try a few other powers...check them out and get some ideas to build your character on.