What are you selling? Where are you selling it? How are you going to sell it?
Shop is pretty easy...for extra grades make sure you incorporate it. Dont just be a sole proprietorship or partnership (loose your *** if you get sued, corp is a sole entity..and is only liable for itself).
I'd keep it simple, 4 bays, sell tires/rims, have 2 lic mechanics and 2 apprentices (less wage).
That should get you going in the right direction.