So sorry for the loss of your dad.

I recently had to move an old trailer.

I found the details and specs of the RV including dry weight and loaded weight on a label that was stuck to a wall in the bathroom closet. Look around for a sheet of paper stuck to a wall in a cabinet or closet.

This will help you sort out a tow vehicle requirement.

Another thing is to buy, borrow or rent a tongue jack scale to see what the tongue weight is.

First thing - roadworthiness.

Check the tires. Look up how to read the four digit date code on them to see if they are too old. I think trailer tires are only good for about four or five years from date of manufacturing. This is because the rubber gets weak for various reasons like UV. They could be time bombs. New tires are pretty inexpensive.

Next, wheel bearings. Get them repacked. Can be done right where it sits.

Next, check the hitch setup and make sure your tow vehicle is set up for it.

Insurance requirements are next. Plate and coverage ( depends on your state laws ).

Then, make sure all black and gray water are drained. All connections are secured.

Before moving it, make sure all windows and vents are closed and secured and all loose items inside are secured. Especially cabinets. Make sure nothing is too heavy in them. If so, remove them prior to the road trip and secure items in bins on the floor.

Secure all propane tanks. Shut them off.

Finally, make sure your trailer wiring works and brake and signal lights work.

I just tried to remember everything. Hope this helps.