Read, Nigga, Read - you just started after all

Write ten pages of backstory, watch yourself be killed by a stupid decision followed by an unlucky crit by a goblin in session one. Several hours of brainstorming wasted.

Just make a brief few bulletpoints. You can expand on them later if you survive.

If we're going to get technical, it's not a backstory if it happens after you start playing the character; it's just a story.