Wife and I came from an I/O to a jet. both 19ft boats. Getting the boat off is no different. Back in, throttle up and it will power right off.
Getting near the dock.....GO SLOW....with short little bursts of throttle. Not too much, but just a touch here and there. Your typical "idle speed" in a jet is closer to 2.5-3k rpm. That's almost on plane with a regular I/O boat. ALSO, these boats don't have transmissions. LOTS of forward/reverse/forward transitions to control speed and direction. get used to really working the wheel and the fwd/reverse situation. I find it VERY helpful to keep it in the first click up on no wake mode. Just let the engine run high the whole time. Then click in and out of forward/reverse/neutral a LOT to control direction and speed. Remember, without throttle you have no thrust. Without thrust you have no steering.
Getting back on the trailer is just like an I/O, Line yourself up, creep in slowly, then give it a little power once you touch the trailer to drive it on. Keeping it lined up is the hardest part if there is wind or cross current.
I HIGHLY HIGHLY HIGHLY reccomend taking a day before Memorial Day to practice at the ramp and docks. A random Tuesday morning or something like that where there are not a ton of other people around to watch you learn. It will release some pressure from you to perform right. Launch and retrieve the boat 5 or more times. Get used to how it feels going on and off the trailer. Get used to how it performs at low speed. It's different than your I/O and takes a bit of learning to get really good at it. I practice touching the nose and the stern to the "No Wake" bouys at our local ramp. If you can ease the boat in and just barely touch the bouy, then you can do the same thing with the "big and scary" dock.
My final piece of advice is to bring a large bucket of patience. Keep in mind, it's just a boat, you're there to have fun, and you have all day. Don't rush anything, take your time and do it your way on all aspects. This will lead to a better understanding of whats happening, slowing down the inputs to your decision making, and in general make for a more pleasant (and safer) experience.
Congrats on the new boat, and be sure to let us know how you fare on your first voyage.