So far as having tanks is concerned: you could borrow a tank long enough to get inspected, or pick up a used tank from a wrecked RV, or makeshift something small and inexpensive (a 5 to 30 gallon water jug/barrel, even?).
For the hose connection, yes, those fittings are very standard and common. Just search your favorite online or physical RV supply for "rv sewer fittings" or similar and you'll be led right to the waste tank gate valves, pipe adapters for the same, and bayonet adapters for connecting the 3" hose.
Keep in mind to use wye fittings with the branch directed appropriately so waste flows the right way, use traps so you don't have odors rising (they will, even if you skip the tank and run hose direct to the campground sewer hookup), and have a plan for avoiding water backup (if the drain hose is disconnected and a cap installed, or drain valve is closed, you may not want waste water from the sink appearing in and overflowing the shower pan for example).