What can I do to settle outstanding debt and improve my credit score

Note that I am not licensed to practice in your state.

First think you need to do: Get rid of freecreditreport.com. Whoever recommended it is wrong. If you want to see copies of your credit report, in which you are entitled to one free copy from each of the three credit bureaus a year, go to annualcreditreport.com. That is the ONLY place to get a free credit report. Note that you are entitled to a free credit report a year but not the credit score. Credit scores you do need to pay for.

The way to fix your credit report is simple: pay down the debts. The more of the debt you pay down, the higher your score will go up. After you pay off a credit card, remember to NEVER close down the account. Closing down an account will lower your credit score in most cases because it lowers your overall credit limit and shuts down your credit history with the card.

One last thing, if you need a co-signer for a loan, that means you cannot afford it. Don't buy anything you cannot afford since that is presumably how you got into credit card debt to begin with. If you can't pay off a car, by yourself, within 5 years time - you either can't afford that particular car, or you can't afford a car at all.