Create a Computer Account

Be more specific, please. What is happening, where is it happening, what error messages, etc.? Please read Writing an effective Apple Support Communities question. We are here to help. We are all users. We are not mind-readers nor clairvoyants. We only know what you write down and tell us. Be specific and thorough. Include your hardware information and installed version of macOS. Try to write clearly. Think about what you want to say before you write it down, then re-read it to see if it makes sense.

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Making progress a little at a time. Are you in the Setup Assistant? If you are, then shut off the computer, wait 30 seconds, then restart. See if that helps. Remember that there are limitations on what characters can be used for an account name and password, especially, the latter. I suggest you use a basic user_name such as, jconnor (if your last name is Connor and your first initial is "J") all in lowercase. Your password should be restricted to letters and numbers. This can be a mix of upper- and lowercase letters. The password should be randomly selected and at least 15 characters long, so as to be very secure. You won't remember the password, so write it down somewhere safe.