The CAN-SPAM requirement means that for every email you send, you must list a physical address for any contact back to you.
If you’re just starting out and are trying to keep expenses down you may not wish to run out and rent a PO Box at the local United States Postal Service (where I live, I priced this and it was between ~$88 to 190/year) nearby. Nor would you likely want to pepper your home address in all your business emails and always wonder about that.
One option if you use ConvertKit as your SAAS Mail Service provider, is that they will let you list their address. Then, they have some additional requirements for you to abide by, but they seem reasonable and sound to me. Check them out here.
You’ll see the address they offer is “113 Cherry St #92768, Seattle, WA, 98104-2205“. If you do a search in your emails, you’ll probably find some of the people marketing to you use the ConvertKit address as well.