added 2 sub domains and now cant get into prime

Well… https://i-love-rochdale.co.uk/wp-admin sends me to https://i-love-rochdale.co.uk/not_found

Actually ALL /wp-admin/ send me to a /not-found/ and that’s sure wrong.

Rename the plugins folder to plugins-old

Tried that Ipstenu nothing has changed, thanks for helping any more suggestions?

all these sites are fairly new and not got much content, should i just start again?
if so what is the best way to do it please?

To start over, just delete it all and reinstall. BUT. Can you possible remember what the last thing was you did before this started happening?