Converting for him?

My boyfriend is Arabian, also Muslim. I’m a regular average American girl. I’m pretty sure we’re not supposed to be together (said by his religion) although he’s told me a few times he doesn’t fully follow it and he wants to marry me and start a family with me in the future. But I’m kind of confused because how are we supposed to get married how will his family feel? Not to mention he lives with his family and they’re very strict about their religion... I’m so confused someone pls help.