For me it's opening a weird Word page with some non-system symbols. I'll appreciate if someone could explain it or send a guide vid.
It sounds like you're trying to open the files, which is something you don't need to do. It's just a case of copying and pasting the files, once downloaded, into the correct location, and then performing a couple of clicks in-game. If something you've downloaded is compressed or zipped into a .rar or a .zip file, just extract the files from that and then copy and paste to where is needed.
To install tactics:
Copy and paste the file into this folder location:
Documents\Sports Interactive\Football Manager 2022\tactics
Then in FM, go to your Tactics page, and Load Tactic.
To install graphics:
A lot of graphics packs will be in .zip or .rar files to reduce file sizes online. Plenty of instruction online on how to extract from that. Once you've extracted the files, copy and paste to the following:
Documents\Sports Interactive\Football Manager 2022\graphics
If the 'graphics' folder doesn't exist, just create it. FM doesn't auto-generate this folder.
Then, in-game, go to Preferences, Clear Cache & Reload Skin.