I'm getting a software update notice but when I click on system preferences and software updates all that comes up is the Monterey OS upgrade?

Big Sur may have an update (aka patch). Unfortunately macOS will put the Monterey upgrade front and center causing unsuspecting users to accidentally upgrade their OS instead of updating/patching it. Look below the Monterey notice in Software Update System Preferences. You may see a link of blue text in very small font which will be the updates (aka patches) for Big Sur. It may be labeled as "More" or "More information" or "More options" (I don't recall -- I just know it is a small blue font that looks like a link -- it is very easy to miss).

I am unclear as to what your question is. What OS are you currently running? If you are running an older OS, this is normal to offer you an upgrade to the newer available OS. If you do not wish to receive these notifications, then open System Preferences, click on Software Update and click on the Advanced button. That will open a window where you can deselect the option to Check for updates automatically. You will have to do so manually in the future.

As suggested previous posting.

And disable ( uncheck ) ALL as per the two pictures below.

Because the computer may qualify for Monterey - the notification may or may not still be presented.

I am in the middle of a college term and unwilling to upgrade to Monterey OS just in case it messes with my work in the college mandated Visual Studio Code. The same update message is on my MacBook Pro but when I go into system preferences it just offers me the update to the new OS. Clicking on the "more info" in blue just leads to the page in my browser trying to convince me to upgrade to Monterey. In the past there have been patches for Big Sur as mentioned above so it is good to keep an eye on. I am just ignoring it for now. Hope this is the right move.

Luck to you with your stuff. I understand not wanting to take a risk when working on things.