8
Ludo-narrative Dissonance
(i.redd.it)
If your character's starting off at level one, they're really only getting started with adventuring. You can let that be reflected in their backstory.
If you want to play a badass, starting above level 1 is allowed, though probably not recommended for new players still learning the rules of whatever system you're playing.
Considering that a real world new recruit who's only martial experience is about 8-10 weeks of basic training would probably be a second or maybe even third level fighter, first level characters aren't very impressive. If there's an actual zero next to "Experience" on your character sheet you aren't a grizzled veteran and you haven't seen anything rougher than a barfight. You probably lost that fight, too.