First time masturbating

So I’m 21 and I’ve never actually masturbated before because every time I get even slightly horny (which isn’t very often) as soon as I try touching myself it goes away and it’s suddenly just me awkwardly trying to get it back. I just want to know what an orgasm feels like. I’m also a little afraid about penetration. I’ve never even used a tampon before! At this point, idk what to do. Should I try getting a toy that focuses on clitoral stimulation?

To be honest, I’ve never really been that worried or curious about it. But my boyfriend really wants to go down on me and idk why but I feel like it’s important for me to get to know myself before I let him. He’s so understanding of the fact that I’m a virgin and not even near ready for sex, and I love him, and I just want to give him this. I’m afraid though that I won’t orgasm, or can’t orgasm. Any tips on how to approach this?