I kind of want to move over to lemmy.ml because I don’t like the content in lemmy.one if it helps I also deleted my lemmy.ml account because I signed up for both and thought I could only have one. Going to the lemmy.ml website now says 404 deleted and I want to fix that.
As others say, you cannot transfer an account.
But you can have accounts on multiple instances. So you didn’t have to delete your old account. You should be able to sign up with a new one without problem.
Not sure what you mean by 404 errors. Try clearing your browser cache and refreshing the page. That shouldn’t be preventing you from creating a new account on whatever instance. (Even if you had an old account there before.)