Sister, you need to start researching how loans and stuff work (you want to be informed BEFORE you start borrowing hundreds of thousands of dollars!!!!). You do not "put money down" on loans...you don't GIVE money to GET money. The loans that you get during medical school will probably come from the federal government (assuming your parents aren't super-rich and that you don't go to a private school that will have tuition that is higher than the federal loan limits). These loans will cover basics like room & board, tuition, books, etc but you can only borrow as much as your SCHOOL has budgeted for you (if your school says that it cost 10K for tuition, 5K for room/board, $1K for books, and 4K for everything else...that's ALL you're getting from the Feds per year, not a penny more) The budgets are generally NOT realistic (they will budget $400 for rent in a town where the average rent is $800) and they usually do NOT cover car payments of any sort (although some schools will throw in a ridiculously small amount and call it "maintenence") You generally do not get extra money for having a spouse or children (although there are SOME exceptions at certain schools for kids) so if you get married, your spouse will definitely need to work.
Anyway, this is just a SMALL tidbit of the info you need to know before you start taking out loans. Try going to <a href="http://www.ed.gov/offices/OSFAP/DirectLoan/" target="_blank">this site</a> to start your learning process!
Good luck!