Congradulations CS, I'm 62 years old and have had a lot of boats, but never a new one. Maybe some day if I live long enough. As for your trim gauge, it is a reference. When you take off from dead stop. trim the motor all the way down to get you on plane quicker. Note where the gauge is pointing and you won't have to look at the motor every time. Once you get going and on plane, start trimming the motor up a little at a time. You will feel the steering getting easier and if you go too far it will start porpoising, again note the setting. Once you get out and play with it, you will learn where to trim the motor for any given speed. I hope I made sense.
Fair Winds and Following Seas
Bill H. PTC USN Ret
Chesapeake, Va