Oh gosh, please don't talk your fiance' into rushing into anything. You'll really regret it.
You'd be very smart to first buy a house. Also it would be great to stay child-less for awhile so you can enjoy each other and perhaps do some traveling, or just go out with friends on weekends, etc. Once you have children, all that comes to a complete HALT. Finances become strapped, time is at a premium, and everyone is dead tired.

Not only that, but wait until you're emotionally ready for children -- a little maturity goes a long way!! Twenty three is a bit young for children -- I had my first at 21 and I should have waited!!! I had no business having a child at that young of an age. Yes, we did own a house, but that didn't mean we were mature!!
So give yourself some time to really get to know each others quirks, have some fun, travel and THEN think about kids. You won't regret it. God bless & take care. Hugs, Lee