@_V_
I’ve got mine running on a RPi 4 with (iirc) 4gb of memory which seems to be enough. I’ve got a lot of modules divvied up into 3 pages that are selected via a wee macropad (three buttons & a knob) attached below the screen. (My dev version has 6 pages and I’m waiting on a new 6-key macropad so I van put that on the main system.)
I don’t have it behind a mirror; it’s just in a wooden frame.
I (and my family) add stuff to our calendars on our computers/phones; the MM is only for display. If I didn’t have to waste 8+ hours a day at the stupid job thing, and if I had more money (college in the US is outrageously expensive), I would try to get touch working so as to be able to go to the next/previous month on the calendar (MMM-CalendarExt3) but I’m happy with it as is.
I don’t worry about profiles – mostly everyone looks at the dinner menu (I have a google calendar just to say what I’m cooking for the next week or two) or the main calendar. Those are on the first page.
So, based on what you said, I would suggest getting yourself a basic RPi – I think the Pi Zero 2 is a little underpowered, but it’s doable – and an old monitor and start playing with it. Worry about installation and all that once you have it showing what you want and working the way you’d like it to.
I’m fortunate in that I have an extra Pi so I have a copy running on it that I can play around with without breaking the one in the kitchen that everyone looks at.