When i try to install GOG galaxy or cyberpunk 2077 it gives me this error. Already try alot of stuff but dont work

Get the latest offline installer for GOG Galaxy. It doesn't need to download any components off the Internet, so you won't run into whatever firewall or connection issue you're having. The first link is for Mac and the second is for Windows.

As for installing Cyberpunk 2077 or any other game directly, they're all offline installers so they wouldn't have the same issue. Ignore the blue "Download and Install Now" button and instead click the "Download offline backup game installers" section to expand it. Note that Cyberpunk 2077 has some content exclusive to GOG Galaxy that you'll miss out on if you play it offline.