Anyone here done professional modeling? Not talking about favours for a photographer friends or designers, but been registered with a modeling agency.

I have never considered it as a main career but am now considering it as a part time thing. I am 5"9, 125 pounds, UK size 8 with a small build. I have quite a symmetric "doll" face. I know you can't give an opinion from that, but friends, hairdressers, even photographer friends have asked me if I do modeling and said that I should. Only thing is that I just turned 22, and most models start out in their teens. However I know there are varying degrees of modeling

I don't know where to start. I feel like it's better to show up at an agency, but am not sure...