Mikal with a k on Nostr: Okay, so I'm teaching myself basic #Photoshop skills so I can make my own basic signs ...

Okay, so I'm teaching myself basic #Photoshop skills so I can make my own basic signs and banners for my cannabis business (and eventually, other things). The image attached is for a banner at a local craft festival this weekend. It works for what it's for, but I'd like one extra element to keep it consistent with our style: a white interior border. See second image for what I'm talking about.

Is someone willing to give me a quick step by step to creating this? Or can you point me to an online tutorial? All my searches kept turning up LLM-generated junk or instructions for putting a perimeter border around an image, but gave me no sense of how to have it offset from the edge.

Thanks in advance!