New to sex- can't orgasm during sex?

Hannah
So I just lost my virginity to my boyfriend a month ago. It wasn't really painful or anything like that and it was quite enjoyable, except that I never orgasm! We've had sex a few times since, but he's in Florida now (I'm in Ohio) because he's a marine. I really don't know anything about what I'm doing but it's really frustrating to me that I don't orgasm. He's tried to get me there, in fact, we tried several times in one night, but I never climaxed. Is this just because I'm not experienced, or...? I'm not really sure bc I'm quite new to this world and I'm still trying to figure everything out!
I will say that I've orgasmed by myself though, so I know it's possible to get me there but that was only with clit stimulation. Sometimes it takes me a while even that way to climax. So other question-is there a way to make it easier to climax?