If you have a weak memory, what do you memorize and what is your method?

Per a recent suggestion I'm working on memorizing the natural major scales, and it seems by doing so it will be very easy to know the minor scales immediately by referencing major scales. I got tripped up on intervals for a bit and I'll be incorporating those as well.

Feel free to take my method below and critique the shit out of it, tell me its garbage and that I'm going down the wrong path or should be doing it totally different. I have a blank canvas right now and I want to maximize that early potential for music theory.

I have a poor memory, age and neurodivergence are a factor. I'm making progress I can quickly spell the major scale with the step patterns, and now that I'm starting with D major, I dont really know how to memorize these scales so my intuition is to remember which notes are flat or sharp. So would it be smart to remember that D major has a F# and C#, or is there a better way to do this?

Also, aside from being on paper is there a way I should be incorporating my keyboard or guitar in memorizing these scales and what should I be listening to/paying most attention to?

Finally, if there are other things to memorize at the start, what would that be? Any tips and tricks for memory would be super helpful.

I'm trying to learn so so much at once and my biggest priorities in music are to develop my ear more and also to translate anything in my head to an instrument. Or to have a kind of roadmap while I'm trying to come up with melodies or progressions instead of just blindly playing notes waiting until something clicks.

Right now my knowledge is very beginner level, I am an avid lifelong lover of music, lifetime player of guitar but not dedicated, and ear-wise I can kinda tell if my guitar is out of tune but I cannot tune by ear unless one string is in tune and I can reference the unison notes.

Thanks!