cannot get my watch to pair with my mac

Apple Watch cannot be synced to Mac computers via Bluetooth. It can only be paired, set up and synced with a compatible model of iPhone.

Perhaps this is what you're thinking of? Use Continuity to connect your Mac, iPhone, iPad, iPod touch, and Apple Watch - Apple Support

If you are talking about unlocking your Mac via your Apple Watch, then

Check out this thread on fixing Apple Watch unlocking Mac

Mac not unlocking after watchOS 7 update - Apple Community

Read the replies, as there are other solutions besides the one marked solved.

OK.....Then BobHarris guessed correctly, so check out the link he provided.