Hello there billy_bob66,
I see you're looking for help with recording your screen using QuickTime, so let's se how we can help.
As you're stating you're unable to pause the screen recording, let's be sure we're understanding correctly. When you start the recording, are you noticing that the Stop Recording button isn't shown in the menu bar along the top of your screen?
For help with recording your screen and reference on where the Stop Recording button would be, take a look at the following resource:
Record your screen in QuickTime Player on Mac
If you see that this isn't present, try a restart of your Mac to see if that clears up what is occurring. If it hasn't cleared this up, it may be best to update to the latest version of macOS Big Sur. For help with that, use the following resource:
Update macOS on Mac
We hope this is able to help.
Have a great day!