how do i delete or remove a profile?

Hi Pulplar,

You should erase your Mac to remove the data left behind by the previous owner.

Use Disk Utility to erase an Intel-based Mac - Apple Support (CA)

Use Disk Utility to erase a Mac with Apple silicon - Apple Support (CA)

If you run into an Activation Lock screen, contact the previous owner and ask them to remove Activation Lock. If they cannot do that, you should assume that the Mac is lost or stolen.

If Your Used Mac Gets Locked - Apple Community

The other person should follow these steps: https://support.apple.com/en-us/HT201065

The previous owner had to do this:

What to do before you sell, give away, or trade in your Mac - Apple Support