I need some advice....

So, I'm 19 years old almost 20 and my boyfriend of two years is in the Navy stationed in South Carolina. Recently we have been planning on moving me down there with him and "starting our life together" before we get married or even engaged - even though we both talked about it and we're going to, he just wants to save up for a ring before he a proposes. The only thing is, I live with my parents right now who are super religious and they're all but forbidding me to move in with him before marriage even though I don't share their views. They're even going so far as to say that they're considering not continuing to help me with college if I do it. They know our plan is to get married and they know we love each other and both my parents like him so that's not an issue, their issue with it is purely religious and "that's just not the way things are supposed to be done." I've already made up my mind about it and told them that I am going to do it, but I guess my question is: how can I make the move and transition easier on and with my parents and extended family? How can I explain to them, politely, that this IS happening and there's really nothing they can say to change my mind? (Sounds very teenage stereotypical, I know, but it's true). Any advice on this and/or advice on moving to another state and/or advice on navy/military life and/or advice on living on your own for the first time and/or advice on living with a significant other for the first time and/or advice on how to get an apartment and good, cheap furniture/bed/kitchen things/other essentials or just any advice AT ALL would be greatly appreciated. My mother won't tell me anything cause she is so against it 😒😔