Opening a workshop on privately owned, zoned residential land

Hey everyone! My husband and I are feeling a little lost on where to even begin, so we’re hoping some of you experts here might be able to point us in the right direction. I really hope I haven't posted this in the wrong section—if there's a more appropriate spot for this, please feel free to move it!
So, as the title suggests, my husband is looking to open a repair shop for inboard and outboard motors. The plan is to set up the workshop right in our backyard at our house. There are already a few other shops in the neighborhood, though they mostly handle different kinds of work.
Does anyone know how feasible this actually is? And more importantly, who should we talk to first? Should we start with the City? The County? The Department of Housing and Urban Development? Or maybe an architect?
We honestly have no clue where to kick things off. I'm sure there's a mountain of permits and paperwork involved.
For the structure itself, we were thinking about putting up a pre-fab metal building—maybe something with sandwich panels or a sturdy PVC tension fabric structure.

Thanks so much in advance for any help you can give!

You head down to your local city hall's economic development office and ask them to give you the minimum technical requirements for that specific business line.

Douglas Ramirez4 said:You head down to your local city hall's economic development office and ask them to give you the minimum technical requirements for that specific business line.

Thanks so much for the tip—I'll give them a call tomorrow!

Hey there, just wanted to drop a quick update—if anyone has any idea what the next move should be, because honestly, the local Small Business Administration office is totally stumped 😁
They told me that I don't need to worry about minimum technical requirements if I'm strictly running a workshop—but, if I decide to add a retail component, then yeah, those regulations definitely kick in. For anything else, they basically just pointed me toward the State Building Inspectorate. I've been on the phone all morning calling offices in a few different cities, but NOBODY is picking up 😁