Trying to clean up my credit....?

I don't have any credit card debt whatsoever but numerous bills I racked up as a youngster that I couldn't or didn't pay. No repos, no liens, no student loans, just bills. Should I go through one of the agencies of just contact the companies on my own and go from there? I really want to consolidate that debt into one sum but I don't think they do that if you don't have credit card debt. Any ideas on what I should do?