You don't have copies of your report from any of the bureaus? I'm assuming you pulled them within the last year. I don't think you can access them later if you don't have the report numbers.
However, if you've been denied credit based on one of them, you should get something in the mail telling you why you were denied credit and you would have a right to a free report based on that. I don't recommend running up inquiries to get your reports that way, but if you already have, you may as well take advantage of it.
I think that you should first stop paying off debt. If there's anything you haven't paid yet, don't - it's leverage for what you want to do.
Second, pull your reports directly from Experian, TransUnion, and Equifax. Do not get them from some other service (including myFICO), and do not buy your credit scores from the agencies either. The reason is that you want the most complete info that you can get, which is only available with direct-from-the-CRA reports. The scores from those sources are not FICOs, so they aren't worth paying extra for. When you pull those reports, please please please make a .pdf of them. At least print them!
You've paid off some of your debt, so I would start by sending everyone who is paid in full a goodwill letter. There's a link at the top of this board about those. Basically, you own up to what happened, you explain why it wouldn't happen again and how you're prepared now to not get in that situation again, and then you request a deletion. When you ask for a deletion, be specific - ideally, you want negative information removed but not the tradeline if it's a loan or a credit card or something like that. If it's a collection agency, you just want it removed, period. Goodwill letters go to the entity that's reporting.
If there's any debt you haven't paid off, I would send them a DV letter - CMRRR. DV is debt validation, CMRRR is certified mail / return receipt requested. You can find an example at the top, I believe. It is possible that you'll get deletions with just DV letters. If they don't accept the letter or they don't respond to it, that's a reason to get them off of your reports.
If they respond, you can send them a PFD - pay for delete letter. Essentially, you offer to pay them if they will put in writing that they will delete the negative info from your reports.
After you've cleaned up your reports as much as you can, you'll want to start working on acquiring some revolving credit.
Hope this at least gets you started - also, read up on here about the individual entities on your report to see what strategies have worked with them in the past. Also, FYI, I haven't personally done this in a little while (about 2 years), and there are probably other options as well now - something about disputing with the original creditor, but I don't know the details on that or its advantages / limitations.
Starting Score: EQ 583 TU04 619 EX 592 (lender pull) 2010