Come up with a persona for the sockpuppet account.
Use Fake Name Generator to create a person whom you feel fits your sockpuppet persona.
Use This Person Does Not Exist to generate an image. Make sure you inspect the image closely and get one that doesn't have any obvious flaws, as they often do. It is worth picking up some Photoshop, GIMP, Affinity Photo or Designer, or other basic image manipulation skills to fix them and change the background of the image.
Get a burner credit card from Privacy.com. You might need it to set up a account.
Get a VPN that you can set to the physical area in which you want your sockpuppet to "exist."
Sources: