Riding dick

Ok so I've had 5 different sexual relationships. I get on top a lot but it's more like going back and forth rubbing my clit against him or putting my head down and moving my ass up and down. I don't think I've ever rode a dick before properly, I want to but somehow when I try sit up it hurts a little and I'm nervous because I don't know how to do it properly😩

Please help? Advice?