You need to work on your credit score..rent to own will require some cash down...and based on experience with low credit scores / people wanting to rent to own if you do not have a credit score that shows a few years of paying on time and not defaulting you will not be able to refinance that "rental" now or later.

What you ought to do is pool your money, grow your savings, and every 3 months check your credit score to monitor what you two need to do to "improve those grades". Be conservative with your spending and do not buy a new car/truck, etc. even if offered a "deal"