First of all congratulations and welcome.
Second: Make sure you download and read Ed's excellent crowd sourced owner's manual for Axis/Vegas units:
Which Vegas model do you have?
Third: Actually you can dewinterize before you leave if you want to. You'll be running the heat all the way down which will keep the water system from freezing (as long as you're warm the water system is warm).
We did this in our Axis one year when we drove from MI to FL and back over Christmas break. I unwinterized right before we hit the road (after running the furnace long enough to get the coach toasty warm) and then rewinterized immediately upon returning home.
To use the furnace you'll need to do three things: fill the propane tank, make sure the valve on the propane tank is open/on and turn the furnace on.