Going solo

Maria • 27
So I'm 20 years old, almost 21, and I've never had an orgasm. I've nevermasterbated either... But I want to. My bf really wants me to try it though so I have a better understanding of my body and can tell him what I like. I want to as well, I want to know what it feels like to cum so bad. I tried grinding on a cloth and it felt soooo gooooooood but after a few secs my legs started cramping up bc it was too low.... Any tips on how to start up on masterbating?