I don’t know if I’m doing this right

For reference I am 19f and a virgin. Sex has never really been a big thing to me. And I'm not horny that often so like a very rarely masturbate and I don't think that j am doing something right bc I have never orgasmed and I really want to. Or maybe I have and just didn't know it? My go to the the good old flicking of the bean. However, I usually find that when it reaches a point it gets overstimulated or hurts and I keep going until I can't anymore. It feels good in the sense of like physically and but like i usually feel up in the air but I think it's more so because theres not the sensation anymktr and that's it's finally over. Which I don't think that's how your supposed to feel. I got the rose toy bc I hear so many people rave about it online but I still either feel nothing or extreme overstimulation for from it. I don't know if something I'm doing is the problem or if that's just me. Me and my gf of a couple months have gotten kind of hot and steamy a couple times and she knows that I'm a virgin so I don't know that if I have sex with her I will be able to figure out or if I just can't do sexual acts right. Does anyone have any advice?