Any suggestions/tips or tricks how to find linux compatible laptop? I can't buy preinstalled linux laptop (system76, tuxedo, purism, etc) because is not available in my country.

Usually I have an opposite problem. Any computer installs linux splendidly, but when you try installing windows it becomes a nightmare to find the right version compatible with drivers.

Anyway, if whatever is offered in your country can run windows, then it should be able running linux too.

When I bought my pc for linux I just made sure to choose the one without payment for windows license.

And without external videocard. It made the price much cheaper. Integrated in powerful processor is more than enough for my work and outdated games.

I chose pc with 16gb ram(modern apps to work quite often need a lot of RAM) and just 250gb SSD. Linux is efficient in space wasting, 250 is more than enough. Don't buy HDD.

I bought intel i5 10400 for CPU, it has powerful 6 cores(12 threads) and good integrated videocard.

If there are some doubts about compatibility left
You can make live usb with linux in advance and if it is possible to check if computer can be running it, you can launch linux literally from usb without installing it. It would be enough to check if it can run, to see that internet drivers are working and you can use browser to surf.

Just look online if people have had trouble installing Linux on it, it can be an absolute pain on some machines and a breeze on others. Lenovo Thinkpads for eg. are usually well supported. Other than that you should be good to go.

If you want to use open source drivers, don't go with a nvidia gpu.

If gaming is not your goal, look for an AMD laptop with iGPU only. You can get the H series for maximum performance, but also power draw, or the U series which are sufficient for most jobs (I'm happy with my 4700U).

Make sure that is has two ram bars, at least optionally. Using only one RAM bar will cost you performance.

Pay attention to get Intel wifi such as AX200 and avoid Broadcom.

Anything ? Lol