I did in highschool. When we broke up, we just went back to being friends. The two of us didn’t hang out as much, but we’d talk about different things when in the larger group.
I wouldn’t recommend doing it. Just because it worked out in my case, I know from watching one of my sisters that it often doesn’t.
I was friends with my husband for a couple years before dating him. If things hadn’t worked out, I know that my best friend would have had my back, but his would have had his back. Which is fine.
I would NEVER date anyone from a bar or dating site. I think it is extremely important to know the person before you start dating them.