One thing I've learned is to not spend too much time on how the Garmin Chartplotter setup(s) are all done. It's very tempting to focus on this unfortunately. This can be very time consuming at the expense of learning the more basic boat's operational aspects. It takes a lot of time to memorize all the Garmin chart plotter settings and what things it can display. Get the basic setup for navigating which should be already setup by default and spend the rest of your time learning and asking questions about other things. The learning for all the Garmin configurations can be learned later while referring to the Garmin documentation and getting help from this forum. If you have Autopilot then sure, learn about that, and make sure it works correctly - try autopilot heading and then change headings to ensure the boat navigates to correct headings each time.
How many days will you have ? IMO you'll need two days; one for going over all the boat's details and the other day should be on the water learning how the engine operates, docking techniques, use of thrusters, etc.
Make a list of ALL things you need doing to get the boat ready for leaving the dock.
Make a list of ALL things you need doing after you've returned from the water and docked and wanting to leave boat tied up and unattended.
Take note of any engine break in advice.
Take note of proper operation of the VHF radio.
If you're going to be anchoring, make sure you know how to deploy and retrieve anchor and line using the windless.
Note where all the hull and gunwale ports are; fuel filling, fresh water filling, the pump out.
Note how the bilge pumps work; check the bilge pump breaker switch(s) so you know how to operate the bilge pumps when necessary. They can be set to manual or automatic. The automatic is what you need all the time and use manual to ensure they work before leaving the dock.
Make sure all the leads/fuses at the batteries are identified clearly.
There's a LOT to learn at first (too much IMO even for two days), but over the months of doing things repetitively you will get better and better and more knowledgeable about how everything works.
Don't hesitate in asking your questions in this forum. There are many knowledgeable people in this forum that will help you.
If you have 1st mate with you, then delegate note taking while you concentrate on what's being said etc. Take photos as necessary to help you to remember things later.
Good luck..... and enjoy.
WELCOME to Tugnuts. 🙂