Credit score

My problem isn’t a bunch of credit card debt or things like that. I have mainly medical debt that got judgements on my credit report but most are 5+ years old now. Am I better off paying the old debt that was sold from when I had no insurance or letting it fall off after the 10 years? I’ve had one credit card in my life and it got canceled because I tried to make a payment and it didn’t hit my bank that day 3 times, so even though I was trying to pay it in full they canceled my card. The only other debt I have is my student loan and I’m in good standing with them. My score is mid 500’s but I want it higher.