Unfortunately, rehabilitating a credit score is not as easy or as quick as its destruction. While delinquencies account for more than a third of your score, there is hope. Implement the steps in the section "Repairing Negative Information on your Credit Report". While solving old debt problems, stay current on your existing debt to have maximum impact for your effort.
If you have no credit or can't get a credit card on your own, explore the option of becoming an authorized user on a credit card. What you do is ask a primary cardholder, like a family member or significant other, if you can get an authorized card in your name on their account. Keep in mind that some scoring systems may give less weight to authorized user accounts than they do to primary accounts, but you would still stand to benefit from them.
The accounts section contains a detailed history of all accounts (open and closed), your balance, and your payment history associated with each account. You should be able to see month-by-month payment information for 7 years of history. Each month will have a symbol next to it that indicates whether the account was paid as expected or if it was late.