Make a new character. The Level of your character is determined by the frag count. There are no real limitations as to what you can do or how you can play your class, but if you are going to show off your character you might throw few guidelines in by which youve been leveling. You should however keep your character within one gametype!
Naturally I would make a hardcore character (mortal), but if you are playing pure Trapsin, (Trap assassin) you might enjoy playing normal character as well (turrets, different nades). Your most obvious tank would be Barbarian, but since he uses swords it may be a better build for ATDM or maybe BTDM rather than 0a. Nobody says you cant use ck, baton (if you happen to play on a map that has one, ie Towers) or Crowbar.
My first character was Godmode, assassin character with.. ranged weaponry for 0augs. Couldnt level him as far as I wanted to, but its a first char after all.
I am planning to make a Necromancer using Corpse Explosion (LAMs), possibly bone spirit (LAW), curses (gas grenade), poison novas (several gas nades or lam+gas trap combo). It is likely that I wont upgrade all of those skills for one build tho, but just ideas here.
And of course being a necromancer you have the ability to summon stuff. So I think Ill go to msn and raise some undead to fight for my cause. Possibly one good golem will do as well

Now to see if server has open spot.