How to fix the black screen on Linux at the beginning of booting the os?

I don't know if there is anyone who faced this problem before, but I tried many solutions for that, and all have failed until I thought of a new solution so, here a list of what is the problem, and what are the solutions that I got through it.

I was exposed to a black screen view when I'm trying to open the Linux, there's no information the black screen has.

note:-
I don't have another OS on my machine just Linux os that I have

here is the list of solutions I followed:

1. I entered the "grub" by clicking on the Escape button then, I tried to connect both "boot" and "prefix" with their own path. I tried this step many times for different drives that display by typing the command "set" to see what are drives I can connect with.

one of them that is when I connect the boot and prefix with it and do reinstall by normal, it does a reboot for Linux but returns me back to the same screen "the black screen"

2. I entered the Linux by USB drive boot then, I used a test version of Linux and then I abled to access the os but there are two problems by that:

First: I can't copy or paste data because I don't use a real user who hasn't root.

Second: there are important files that I have in the "home directory" on Linux but when I accessed them by USB I couldn't access them, in other words, the "home directory" of the experimental version contains its own files and don't have any files belong to me on it.

so, the question is: what are the methods that I can solve that problem without losing my data?

thank you in advance