Agree with what's said. New service to shop/Rv is much more costly than running a new circuit off your main panel to a sub panel or simply to another outlet......IF you have the capacity left in your main panel.
Even if you don't, splitting your main panel in the house to a sub panel Next to it and then running a circuit to the RV is cheaper than a new service, typically. (Unless it's an unusual situation where the Rv is 100' from the pole and the house panel is 1000' from the pole or something like that )
Whatever you do, I'd advise on not cheap ing out on the extra circuit especially if it's going to a shop, and DONT direct bury. Put it in conduit so the next guy isn't screwed if repairs need to be made or upgrades are wanted, in the future.