My iMac is running OS Sierra 10.12.6 I am not able to use the audio in ZOOM because it requires a newer OS. Can I update my Sierra 10.12.6 to an intermediary OS and, then, update a second time to get recent capabilities?

My iMac is running on OS Sierra 10.12.6. I need to update it to a newer operating system as this is soooo out of date. The recent issue is that during a ZOOM meeting I was unable to produce sound to the group without using telephone audio through the leader. I would like to know if there is an OS I can update to, and then, secondarily, update to the most recent OS. This iMac has been a trooper, and I'd hesitate to et rid of it, IF I can update it.