Product: Credit reporting or other personal consumer reports

in XXXX, I was working at XXXX and I purchased myself a new XXXX XXXX. All the payments were made on time, and There was not a single payment shown as late until I sold the car during COVID in XX/XX/XXXX. I am certain I completed all the correct and necessary steps to ensure that the sale was done properly, and as I sold it to XXXX, I had no issues, I worked with the credit union ( XXXX  ) to ensure the 10 day pay off process, and according to them at the time of sale, There were absolutely no outstanding issues, late payments on record, or anything else. I reported this to one of the credit unions, with the intention of doing the same same with the other two. However, once that showed It was verified as accurate, twice, I am extremely frustrated. I attempted to call them and was unable to reach a human during regular business hours. 
My mom was a cosigner on the car, So this isnt just affecting me. Not only do I not own the vehicle anymore, I was paid for the vehicle, and I worked in finance at a car dealership so I know what steps to take and what the consequences are of late payments. 
Additionally, Im not sure if I have to open two disputes but the Target credit card that is on my account : They took me to court, and I hired an attorney and everything, and there legal representation never even showed up to the hearing. In my understanding when a judge dismisses without prejudice, it means that the company can come back anytime and ask for the money. But it has been over a year, and I havent heard anything from them, other than a letter stating they sold my debt. It just has to sit on my credit score until they decide they want the money? 
I understand Im not excellent at managing finances, in the last few years much of it has to do with Covid, a seriously traumatizing wrongful termination law, And the death of both a coworker, my father, and my grandfather, in a short succession. Im not trying to squirm out from under my responsibilities, I completely accept that for the second time in my life, I have to work my way out of a difficult financial situation. 
Corporate America isnt just making it more difficult, but nearly impossible. Considering I have just started rebuilding my life in the last year, I also admit, I wasnt able to deal my financial issues, as I was in and out of XXXX  and XXXX XXXX for a XXXX  attempt preceded by a complete XXXX  and XXXX  XXXX. 
I am finally able to focus on the aspects of life, which arent eating, sleeping, and having a roof above my head. I want to be responsible and pay my debts, but If just make payments, Ill just be making payments on interest, which doesnt seem conducive to climbing out of the hole. Additionally, I am unable to get a consolidation loan without working on bringing my credit up. I dont have credit cards anymore, from my research I also dont have enough debt for a third-party to assist ( that Im aware of, anyway ) and I dont have loans out currently, so the only feasible route for me to improve my financials is to first address what I am capable of fixing- Which starts with removing the inaccurate items on my credit report. I am happy to provide or located whatever documentation necessary. 
I appreciate your assistance, and am hopeful this is one of the first steps in the journey of moving from simply existing, to actually living again.