I've been trying to figure out how to get my hands on a supposedly free copy of StarCraft original and even brood war, if they're here, but I haven't found any links or anything that led me to the supposed free versions of them. I don't know if I missed a detail or something, can someone help? I am confused and probably missed a detail that I didn't bother to check up.

You can freely download Starcraft Broodwar via the Battle.net app.

... Which can be downloaded here: https://www.blizzard.com/en-gb/