Any Advice?

So i've been dating this same girl for a year and almost 2 months now. We've had a few discussions about having kids and starting a family, I really do have a great feeling about her, we've been recently talking about getting an apartment or maybe even trying to rent a house (I feel apartment is a much better idea) because renting a house is just a waste of money, it's like leasing a car, only morons do it or people that are in the position where they HAVE to do it, but in our situation we just want our own place to ourselves, sort-of-thing.

We've also talked about kids, the names of our kids, etc etc. We definately have a serious relationship with the little mishaps that everyone has.. but does anyone have some words of advice? She's almost 18 and i'm 20 if that makes a difference. Thanks people.