Zor'kylo the Grand Primus
History
Early Life
Even if there's not too much to speak of, try to give some ideas as to their upbringing or what they've been doing prior to being played. As with any section, rename as you see fit. Perhaps you might need another section with its own title if there's a lot to say.
Adventuring days
Now its time to fill out what your character has been up to as a player character. This will expand into many sections (hopefully) as time progresses and you get some action under the character's belt. Come up with a better title than I have here for this and future subsections.
Appearance
Give a nice description of the character's appearance and choice of clothes in whatever situations you think are appropriate. You can also go over how this has changed over time with reference to their experiences.
You can talk about their equipment as well, or leave that for later in the abilities section. Up to you.
Personality
What they're like, their outlook on life and how they come across to others. In time this will also fill out with how their personality has changed over time.
Abilities
Provide an idea of their known competencies, skills, powers and abilities.
That's pretty much all the main bits and pieces I an think of, but feel free to add, remove or alter any you don't like!