Unpleasant surprises with the trial version

I just downloaded and installed the trial version since I have a new PC with windows 11.

1. Why can't I find any manual? I only found a web page, split into a large number of pages. Do I have to copy the manual for the version I have used during the latest 11 years?

2. My screen resolution is 1920*1080. And I have used the recommendation to have everything scaled to 125 %. PE told me that the screen resolution was too low, so I had to change the scaling to 100 %. Which means that text in my office program, email client and web browser is too small. How do I solve this problem?

3. As soon as I have checked that the program works on my PC, I plan to pay for a "digital key" (or whatever you call it in English). But where am I supposed to enter the code? I thought I would be asked by the program to enter the code somewhere, but instead it appears that I am supposed to do something somewhere when I have logged into Adobe's web site.

4. The program appears to assume that one is connected to the internet when using it. Will I be able to use it when I am not connected to the internet? Older versions of the program I have used without internet, so I am confused.