How to spot a safe game download
Get a game from its developer or an official store. Steam, GOG, Epic, itch.io and the studio's own site are the places that matter.
Check the address bar before you click. Look-alike domains are a common trick, so type the store address yourself or use a bookmark.
A page that offers a paid game for free is a catalogue, not a store. Your antivirus may flag the installer: check the file on the host before running it, and keep the install folder out of your backups until you trust it.
Open-source games publish checksums or signed installers. If the developer lists a SHA-256 hash, compare it after downloading.
Keep your system updated and use the antivirus that ships with your OS. That is enough for games from official sources.