Trouble with Different Positions

I lost my virginity to my boyfriend 4 months ago and the sex has been getting better, but lately it’s been almost boring. We only do missionary and it’s good but it’s the same thing every time. He’s slept with other girls before me and they only did missionary, he’s never done anything else. I’ve brought up the idea of trying different ones like doggy, and he’s more than excited to try. He’s just really confused and doesn’t exactly understand how to do it, which I ended up explaining to him.

We tried doggy once and he couldn’t get it in. He did eventually for 3 seconds bc he leaned all the way forward and it slipped out. Also the whole situation was uncomfortable (where we were, weren’t home alone) so I felt awkward and ending up going back to missionary.

I’m just asking if this happened to anyone else? Any tips or help of any kind would be appreciated. I’ve dealt with other people being pretty rude and calling me and my boyfriend dumb so I’m hoping not to get any of that. Thank you!