Congratulations on your acquisition of 'the best slow ride' you'll ever take!!
We love our R21 EC as it provides a calming journey for an afternoon on local lakes or for a week along longer waterways. We had ours about 2 months and did a week on the Erie Canal. We got lots of looks and comments about the 'Baby Tug' as we cruised.
Maintenance is pretty simple and operation is not complex for the novice. The first few times out, find an area that has no nearby traffic and take the time to 'mess around with it'. I mean, learn how tight it will spin in a circle, how to use the bow thruster to 'push' off of a dock, figure out how much throttle it takes to bring it to a stop. Stuff like that. It will help your learning curve.
And one thing I learned was NOT to fill the fuel tank all the way up unless you're going to travel a long way (over 100 miles) on a trip. For reference we traveled 145 miles on the Erie Canal and used about 8 gallons of fuel. REALLY. This boat sips fuel...
Enjoy the ride! Invite your friends for some great times!