newbie weekend user need advice

Taking the wheels off won't hurt anything. For winterizing, drain all the tanks and hot water heater. Then use an air compressor set at 40lbs and blow out all the water lines. There are many YouTube videos on how to do it. Then pour some RV anti-freeze down all the drains/traps and toilet. Should take you about 20 minutes.

hook it up just like a house bury the lines ,put it on blocks no problem. mouse proof the under side first. fill every little hole .a mouse can get in a hole the size of a dime. if mine I,d plum it in so I had valves to shut of water and drain easy ,.

If its gonna be freezing , put water in tank upon arrival and empty when ya leave . Place a small heater under the trailer and skirting the few days that you are there ,.Drain all when ya leave . How cold do it git ? And for how long ?

the hill country can experience low to mid 20's at night then warms to low 30's during the day. just a few hard freezes but on those wknds I wouldn't use the water

Regarding your question about pouring water down the toilet after #2 - couple of things here - it may freeze and solidify taking a while to unthaw and drain when you need it to. We were told by an RV Tech to put rock salt in the black tank to keep it from freezing, but we never did. We were worried about the salt causing corrosion issues, eventually, plus we didn't camp for more than a couple of nights when the weather was freezing. A better solution would be to completely winterize your unit, including the tanks, and when you plan to use it for a couple of nights in freezing weather, carry along potty packs - chemical that you put in a bag and use that over your toilet (using your toilet bowl like a holder). You can camp in freezing temps using basins to catch your wash water, etc. If you run your heater and the vents are designed to keep your tank from freezing, then you wouldn't have a problem using the toilet and then dumping it at the end of your stay.

After removing the wheels and sealing all you can underneath, consider skirting the trailer. It will help protect the tanks, and make it relatively easy to add some heat to help protect the tanks when you are there. Even a 75 watt lightbulb can help considerably if you have it well enclosed, and a tank pad will also have an easier time.
If you will have electric power available full time, you may want to permanently install some heating appliances.

If you have lived in that area very long you know in any given year you may not see the temps drop much or any below freezing thru the hunting season. Or it may drop into the low teens or even single digits. I have hunted near Fredericksburg as low as 12 degrees in December. But nothing near that in a number of years.

Skirting is a good idea with one or more light bulbs under the trailer if you have electric. If you would like to have full use of the facilities (sink, shower, toilet) and the forecast is for temps not to get lower than 30 degrees or so, carry water with you (in jugs or water bladder) and put into your fresh water tank and enjoy the convenience. And drain all water lines and water heater and blow out the lines with a portable compressor before you leave. Unless you are planning to return before a hard freeze is forecast. If a hard freeze is forecast for your time there, then only use water jugs to pour water down the toilet. And drain before you leave. Buried drums would work as small septic tank.

Or just use the woods to do your business. Been there, done that, but in my younger days.

thanks for all the advice folks, looks like I will block it, take wheels off, try to seal any opening that mice & rats will try to get into, spray foam on tanks, wrap any exposed pipes with foam tube, install a few lights underneath and then skirt it. Not sure if I'll get to all that for this winter so I'll make sure it's winterized and just use my bucket toilet for now until the spring.

The guy I bought it from had the water hooked up when he showed it to me so I can see everything worked. I opened the two valves to empty the water from the black & grey tanks but I didn't know about the water heater so I'll have to empty that as well and look for the low point drain to get the water out of the fresh water tank. I don't have an air compressor so cant blow the lines yet.

If you have a septic why would you use a bucket to c rap in? Use the camper, then dump it before you leave if you think it will freeze.

When you get to the light bulbs underneath look up thermo-cubes basically an inline plug that only turns on when temps get cold.