Do I need a lawyer to obtain documents to sue my adopted parents?

It is hard to know from your questions exactly what your remedies will be.    I assume you are an adult now.    At the time, a call to CPS would have been appropritate if there was abuse of neglect.   I do not see any mention of that, or details of why you were available for adoption in the first place, how old you were at the adoption, etc.  Civil suits have statutes of limitations just like criminal suits, so the amount of time that has passed will affect your possible recourse.    If you are only recently adult and the neglect happened in the last few years, you might be able to bring a case.   If you are more than 25 or so years old, it is probably too late.   Being able to bring a lawsuit is very different from being able to win that suit.   Being left outside all day may not be considered abusive to the court (the court hears a lot of terrible abuse cases every week), there are many details that would have to be elicited.  Even if you do sue and win, your recovery would be limited.   If the adopted parents don't have significant resources they might not be able to pay a judgment.    You will definitely need an attorney to do this - you can't pick up the skills you'd need quickly enough.   Look for family lawyers in the county where you and the adopted parents live.   It will be very expensive and you have a low liklihood of winning.  I can tell there is a lot of pain and anger, so some time with a therapist may be a better use of your time and energy.