Mike, I just remembered, the Horizon has the Xite "GPS Infotainment" system installed. We have the same unit. I just want to caution you that it's a bit different in the way it works. It uses Rand McNally for GPS and that system works differently than Garmin so you might want to take a look at the RAND operations manual before you pick up the RV.
I really like the system. But there a plenty of others that hate it. Some even go so far as to remove it.
Take some time, learn the system, UPDATE the software as soon as you can on the SD card and you'll see it's pretty powerful.
To update the SD you remove the card (It's located in the Core Unit ask them to show you where it is at PDI). You'll need a computer or laptop and you'll need a SD card reader if you don't have one.
Then you go to the RAND website and download their DOCK software to your computer. When you launch the DOCK software it will ask you to insert the SD card in your reader. Register your system (you'll need internet for all this naturally) and you'll see options to update your system if there is an update available and if not you'll see update your maps. They update the maps pretty frequently so that will probably be the option you see.
RAND has a trip planning website - it's not the easiest to use but when you get the hang of it it's fine. One of the options you'll see in the DOCK is to transfer a trip from the RAND trip Maker website to your SD Card.
Here's some links:
This is what the GPS system will look like and how it operates:
Here's a video - it's for a dash mounted unit BUT it's exactly the same software as you'll have on the Xite System:
DOCK download - scroll down to the DOWNLOAD section:
For some reason RAND doesn't list the Xite System. So, if it asks you for your GPS unit choose the RVND7 option. When it tells you to connect your device, that means to insure the SD card into your card reader on your computer.
Here's the RVND7 Users Manual PDF - ignore the device mounting, etc and take a look at how to enter locations and find campgrounds, etc. The software will look and work just like your system. You'll get all this in your Operator's Manual in the suitcase they give you. But if you want to plan ahead.:
Hope this helps.