I have a 30amp outlet on my house to supply power to an RV but I plan on putting a portable building near this area and would like to use that power to power my shop which will include 12 3D Printers which are not high wattage but constant draw similar to running 24 100w light bulbs. And also power a small heater or ac unit and a few small power tools occasionally like drills sanders and Dremals. What is the best way I can tackle this using the 30amp power source?
Assuming that the RV power outlet is 240V, then when you build or buy your building, put in a small load center with a 30A Main Breaker with separate circuits for the building outlets. That way you can't overload the RV outlet and it gives you the required individual circuit protection for your building. I have that exact same setup for a small office building on my property.