Quick question. Can you run a (retail) business on your “home” lot?

It would have to be listed as retail, but it won't let you change to that while you live on that lot. You would have to move, then pick the lot you want to be retail, change the lot trait, buy it and if you place what will be a home make sure doors are locked so customers don't walk in there and only go in the store you have on that same lot. Some people add an upstairs or downstairs inside their stores for living areas locked to anyone but their households too.