First four things to do..... start charging the battery....... download and read the manual........ download XChange2 software and manual........ read the owner's manual again. Links to the manual and XChange2 can be found on the Classroom site.
You're familiar with the Safari and SE Pro. So basic FBS terminology is familiar to you. When you've read the manual and are ready to step out the door, I'd recommend that you start out in some of the factory programs. Keep the Sensitivity on Auto (or Auto + offset) until you get familiar with the sounds of the detector. Take a look at the coin chart in the Classroom so you know what typcial coin TID's will be. Scan some of your own treasures to get a better feel for the sounds and TID numbers. If you don't like the sounds, remember that the CTX allows you to change those tones, as well as edit the size of your bins in the audio profiles. If you would like more specific "advice", let us know what types of targets you hunt for, and some of the settings you use on your SE Pro. There are a lot of folks on this forum who have used Explorers and can "relate" to the cross-over.
And finally, since you're coming from the SE Pro, get longer handles put on your digging tools. JMHO HH Randy