Nice looking TT!
A lot of campgrounds around us (in New England) have "grey water sites" (or similarly named), which means the site has a grey water only dump on it. Usually it is just a 1 1/2 inch PVC pipe sticking up a couple inches out of the ground, leading down to a hole filled with gravel. VERY convenient for showers and cleaning up, without paying for a "full hookup" site.
Otherwise, we use a small, low bucket in the kitchen sink when we wash dishes to catch the dirty water. When it is partially full, pull it out and empty it into the toilet. This helps fill the black tank with soapy water so it dumps better.
"Navy" showers! Yep, good to learn and easy to do. Wet yourself down in the shower, then shut off the shower. Soap and lather up. Turn on shower, rinse off as quickly as you can. Shut off shower. You might be surprised how little water you actually need to shower when necessary.
PLEASE don't dump grey water on the campsite!! You have a 15 month old... do you want him to be playing in some previous camper's grey water puddle?
Have fun, and see you on the road!