I see thanks but do I need to remove anything on the dns settings page or only add? because ionos my previous registrar has some info on the dns settings as well
Your existing A and AAAA records point to Ionos. If you are no longer hosting there and using Wordpress instead, then those will be replaced by Wordpress IP addresses.
You can’t have a CNAME for www if there are A/AAAA records for the same. Either use the IP addresses, or remove the A/AAAA records before adding the CNAME.