new to here. help needed

Hi

I have a debt company chasing me for a debt that is over 10 years old. This has gone from my credit rating etc. What can I do to stop them.

Also I have a 4 year old ccj showing on my credit rating which I have no idea what it is for because it does not say. what can i do about this Your help would most appreciated.

thanks in advance

new to here. help needed