I would start with the collections that are non government to build some confidence and get educated on this forms on the Debt Validation and State Laws on Collections. Depending on what state you live in they may be noncollectable..
Once you have weighed/educated yourself on the potential risk then go for the gusto on those. That's what I did here many moons ago I shall say.
Once I had my confidence up due to education I would look into the collection issues; I have never had a judgement so I'm not familiar with the process.
Student Loans; you have to call the department of education and people and see what you can do to work that out. If they are old reporting and you paid off. I would still call them to find out all the info I can get. Remember to write down the info they give you on Your Note Pad PC or Pen and Paper. Then adjust your approach accordingly. It takes time and action; but the sooner you start the sooner it will clear up...
Take notes like names and time and suggestions from the folks on the other line; it helps with the thought process to formulate your solutions.