I check to see if it has 5ghz and 2.4ghz. Maybe check advertised mpbs since higher is better although a wifi card actually reaching speeds of 300mbps is laughable and I’ve never once seen it.

Most motherboards come with relatively decent wifi on board but cards are an option if necessary. In terms of specs I usually just look for something that supports the latest WiFi spec (ax).

If you’re going to be a long distance from the wireless router then you probably want to find one with an external antenna that you can position to your liking.

The biggest thing (in my experience) to watch out for is driver compatibility - check the reviews to make sure users with your operating system aren’t complaining about frequent disconnects or other driver related issues.

And remember, unless you’ve got some serious equipment, you’re probably never going to fully utilize the 3+Gb speeds many modern cards boast.