DB,
Expect, well, really, demand an effective briefing before the flight as to some of the expectations, and debriefing following the flight as to observations. For some flights I have done with other pilots, the briefing before hand took longer than the planned flight - 'saved time in the air.
Air is very much more compressible that road or water, so expect the aircraft will be "mushy" in control, compared to a car or boat. Just get used to it, it'll be just fine. That more mushy control is compensated by that reality that aside from precision relative to the surface of the runway, precision compared to driving is otherwise not required.
Similarly, brakes and steering in planes is poor compared to cars (have you looked at the size of the brake pads compared to a car?). They're sloppy things to taxi, so take you time, it'll come to you. It is mechanically not possible for cable type flight control systems to operate with the precision of car steering.
As for instruments, ignore all but: "The Ball" - very frequently when aileron or rudder is being, or should be being used, Altitude, occasional glance if you've been told to maintain it at a stated value, and airspeed, occasional glance during climbout, or approach. Everything else is a nice to know, but should not distract you from flying the plane by outside visual reference.
Use of the rudder: If the wings are not level, and/or you're using the ailerons at all, you should be aware of, and probably applying some rudder. Refer to "The Ball" above. Obviously, the object is to use the rudder to keep the ball in the middle for most flying (passenger comfort). I took a young fellow flying once, and asked what he'd like to see or do. He told me he wanted to understand the use of the rudder. I demonstrated with the application of rudder, and reference to the ball, and let him have at it. He spent about an hour totally focused on flying straight and in turns, with acute attention to the use of the rudder (I watched out for traffic). After that hour of flying, and his dedicated attention, he really did get it. So give yourself that hour of understanding the rudder, with no distraction (from your instructor).
Mnemonics: I have succeeded for more than four decades of flying while completely ignoring the use of mnemonics . Some people find them helpful, I do not. There is no requirement for you to learn nor apply mnemonics to become a good pilot. You've got to do the required actions, but if mnemonics is not your thing, find the method which works for you - which could and should be reference to a written checklist, and do that. As long as you are correctly carrying out the actions, in the required order, how you do it is up to you.
Instructors: They're people, just like us. Some are excellent, and very experienced, others not so much. Couple that with their personal interest in your progress, relative to theirs, and the "fit" could get better or worse for you. It's your money, hire the instruction which suits you. If the instructor is not putting you at ease, and creating a safe and stimulating learning environment for you, discuss that with them, and consider moving on to the next available instructors. It is a reality in aviation now, that the instructors of the day or no longer the highly skilled retired airline or military pilots, but rather new pilots themselves, for whom instructing is a stepping stone to the airline job they really want, so they don't know it all either ('cause they only know what their instructor taught them). The problem is that often they don't know what they don't know - you might be the first to know! Try to find an instructor with grey hair, it got that way, 'cause they have learned more than the basics!