Not sure what to do to upgrade from 23h2 to 24h2 and other questions I have

[MOoD90s 0]

Disclosure: I'm not very tech savvy.

I am well aware that next week is the end of support date for anyone in 23H2 (home editions), like myself. To be honest, the reasons I simply stayed on it are divided in "it looks like everything is working all right" (and all my cumulative updates installed quite nicely, not errors whatsoever), and "I have to back up my stuff first" (which is also the reason I am doing this very late, as I just recently was able to get an external drive). And, sure all the little negative things I read about 24h2 simply didn't make me trust in making a step to upgrade earlier this year.

At the time, I also received a notification that my laptop was able to make the upgrade, but I was suggested to use inControl to suspend that for the time being. I suppose that hasn't changed much, if I toggle it off or something.

Now, the one time I ever went through an upgrade, afaik, was with my previous laptop with Windows 10, like 5 years ago. I was basically forced since it was automatic and the laptop only had about a few days of use with the internet turned on (it was previously owned, had factory reset - gave me so much troubles later on, as it had issues of its own hardware that I was never notified before buying it and I had to find them myself ; it eventually had Microsoft Updates blocked by a computer technic, and I didn't move anything else there since). With previous Windows OS, I stayed as long as I did as such with Windows XP, and especially Windows 7, under older computers I used back then. So, I never had the "honor" to go through this upgrading process more "organically" in my adult years.

So, I'm painfully aware I'm asking this pretty much at last minute, but frankly, I feel like my head hurts while thinking in all of this, because I wanted this whole process to go smoothly, and I'm not even sure if it will be like that (I was also suggested elsewhere to do an in-place upgrade, if the EoS passes... but I feel even more lost with that).

So, questions:

1. About inControl. My first language is not English (although I do understand it quite good), and I went through the GRC's website page to read what to eventually do to "give Windows control back", but... let's say I want to upgrade to 24h2, and stay in 24h2 for the time being (I also know 25h2 and 24h2 barely have differences in their systems right now, I'm not gonna question it at the moment), if I give control back to my computer so I receive the upgrade (?), I should simply edit the spaces where it says something like "11 / 24h2" like that? Should I still receive the free update before the EoS date arrives?
   
   
2. I did some things in registry to edit some things that annoyed me (especially in regards to web searches in the start menu and such; I say "I'm not tech savvy" but I followed an easy guide and I did this all very early when I was just setting up my current laptop)... and I even was able to add Group Policy Editor (through command prompt, iirc). I later found out Group Policy Editor isn't a feature supposed to work with Home editions (it seemed to have worked in "disabling" Copilot, though). Does this affect anything during the upgrade or...?
   
   
3. I suppose I shouldn't worry much about upgrading maybe affecting two profiles I have on my laptop (one is local, the other is connected to a Microsoft Account; both have "administrator" roles). But, in case an in-place upgrade is supposed to happen, are they still unaffected?
   
   
4. I read elsewhere about Windows making a "backup" or something about the older OS version staying behind in case I change my mind in upgrading to 24h2. I have also seen that it supposedly takes over 30 GB of space or smth? What does it actually do? How I should "delete" it in case I don't go back?
   
   
5. That being said, how long does it take (average) in upgrading? What does it depends on? Let's say I have 200 GB of files occupying space in my disk - does that affect the upgrade in any way?