The items will appear on your credit report for 7.5 years from first delinquency, whether paid, settled or unpaid.
After two years the effect of these accounts on your credit score starts to diminish, and by the time they age of your credit report they have almost no effect on your score.
If you want to increase your score you need to re-establish good credit. You need at least 24 months of consistent timely payment history do that. Either credit card payments or an installment loan, or (preferably) both.
Although paying off derogatory items does nothing to raise your score – it’s the right thing to do, and it DOES improve your credit. Your credit is much more than just your score, and when future lenders review your credit report, paid debts look much better than unpaid ones. See why-pay-off-debts.html for more information.