How do I set up a new email? I do not want to invite someone. I need to set up another Comcast email on my account
When logged in as the account owner, you can access 'Users' and create a new user, which creates a new email account as well.
@ferrari0127 wrote: ... I do not want to invite someone. ...
Add the user as a "Viewer" (formerly call "Restricted"), fill in all the info, and save. Then, if you want, "promote" the new user by editing their ID and changing their role to "Manager" or "Member" (formerly "Unrestricted with billing permissions" and "Unrestricted"). That bypasses all the "invite" nonsense.
See https://www.xfinity.com/support/articles/adding-new-user-names-or-email-addresses, https://www.xfinity.com/support/articles/designate-users-restricted-or-unrestricted and the links on those pages.