This system generates a randomized background for a character. It's a strictly optional part of character creation and is mostly intended to flesh out your character and to spark ideas. If you don't like a result, or it doesn't match the concept of your character, just pick something you do like instead, or reroll...or come up with a more compelling option.
It works a bit like Mad Libs. Follow the parts in red and roll on the indicated table where appropriate. Once you get to the Tour of Duty section, roll once per level for levels 3 and 4, twice per level for levels 5 through 7 and three times per level for every level beyond that.
Once you're done, do the exit questionnaire, particularly if your GM allows the mechanical bonuses. Now that you have a mass of random, but hopefully interesting data, flesh it out and turn it into a story.