Regarding your credit, the most important thing that can affect your chances of getting a loan is an outstanding collection item. You can either pay it and make sure that you keep a receipt give to your Financial Institution or dispute it. Keeping your credit in good order, means making at least the minimum monthly payment and don't go over your credit limit.
Check your credit score, see if there are any issues, so that they can be fixed and put you on your way to better rates.