Question about car hauling
 

I've been away from trucking for quite a while but kept my CDL, but now but I'm looking to buy a car hauler. I'm going to be hauling cars that i've purchased from car auctions and bringing them back to my car lot (PA, WV and FL back to OH). Before I drop the cash for a truck and trailer (Freightliner M2 Business class Tractor/Kaufman 4 car trailer) what are the proper steps that need to be taken?

Do I first register with PUCO or USDOT or both at the same time? Does the truck have to be inspected before I can apply for PUCO or USDOT? Not sure how all that works? And am I forgetting anything?

Thanks for the help.