For the SD card update search and load 'RandMcNally dock' software to your computer - then link your SD card to the computer, register it by inputting the serial # and follow the prompts. If you get a prompt that you need a larger SD card the manufacturer will send you one - and alternatively I believe they will still update your card if you send it in.
If you work through the system menus you'll see options for what each screen can / does show. I keep my NAV on the main screen constantly, temporarily interrupted by turn signal and rear cameras as used. I keep the small screen permanently on the rear camera to keep an eye on the toad.
2015 Itasca Ellipse QD | 2014 Jeep Grand Cherokee