Things you should decide about your character:
1.) Short backhistory (What have you done since the war?)
2.) Personal Goals and ambitions (What drives your character?)
3.) Political beliefs (What factions do you support, if any, and why?)
4.) Religious beliefs (What gods do you worship, if any, and why?)
Things too keep in mind- Each class and faction has unique attributes and starting gear. Think carefully about what fits the character you want to play best.