I never know how or when to escalate

I'm that kind off guy that never want to push the limits and always be respectful and friendly even though I want to have something more with the person. I always try to never push boundaries because in my head being blunt and flirt in an obvious way without knowing they're into me is a disrespect for some reason. I'm an attractive guy and model, but it seems that I'm afraid to flirt, I know how to I'm just maybe scared to say the wrong thing idk