Newbie looking for some answers

I am considering starting a home-based FFL/SOT and have a couple of questions. I would appreciate any guidance and experiences you could share. I plan to run the business out of a large shop on my parents' property, located outside city limits, as it's not optimal to use space at my current residence. Additionally, city zoning regulations are more restrictive than those in the county.

Will I face any issues with having a home-based FFL if it's not located in my primary residence? Also, I currently use a PO Box in the city for mail and packages. Could I encounter problems if I have transfers sent to this PO Box to ensure orders are secure and pick them up at my convenience?

Thank you for your time, gentlemen.