Is there a way to find out what debts I owe?

CrunchyHorse

First time posting, so apologies if this is in the wrong place. When I turned 18 a few years ago things were a bit of a mess. I’d take out new phone contracts/gym contracts every few months then completely lose track of them. I had a £50 unplanned overdraft that spiralled out of control with fees so just opened a current account with a new bank and forgot about it. I got a CCJ for an unpaid fine, and god knows what else!
My credit report doesn’t show any defaults, though I moved around every few months so that might be why. Does anyone know if there’s a way to check what/who I owe? My life’s finally becoming stable so I’m hoping to get all my affairs in order and get everything paid off so I can hopefully get a mortgage in around 5 years time.

Thanks