[@NecroKnight]
All of this explained quite clearly in the opening post, if you'd care to read it. What your character's occupation is is up to you; naturally some things will be ruled out like royalty, etc., but hopefully you can come up with something not quite as outlandish.
If you're asking whether your character can be a guard of Kvatch, then yes; but they would have to leave the Guard following the closing of the Oblivion Gate in order to journey with the others.

[@Sleeth]
If this application is the best of your ability, then I'm sorry to say you likely won't meet our posting requirements. This is high-casual to low-advanced, and what you've put forward isn't meeting our standards. Thank you anyway with trying, and the best of luck in your future endeavours of writing.