I *think* you can record without Pro - but - you will need it afterwords, I am sure...
A QuickTime 7 Pro registration key (code) can be used to unlock editing, converting, and exporting features in QuickTime 7.
About QuickTime 7 Pro registration keys (codes) - Apple Support
I would suggest utilizing the in-app "help" [ in QT Player, choose the Help Menu > Quicktime Player help ] and then 'searching' for " recording video and audio " and reading up on the processes - there will be some setup steps before you get started "Doing" (plan your work, work your plan)
To make your video recording - choose "New Movie Recoding" from the [File] menu
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