Hi v2gearup,
Welcome to the Apple Community, where some of us do our best to help each other :)
To work efficiently with individual frames you might need a professional editing application, like Premiere, Final Cut Pro etc.
Yet there is a lot you can already achieve with "trim" tools. both on your iPhone or on your Mac.
Apple support have this article online that may help:
Edit video clips in Photos on iPhone (includes using the trim tool)
https://support.apple.com/en-au/guide/imovie-iphone/kna25483dbe6/ios
or
How to edit videos on your iPhone, iPad, iPod touch, or Mac
https://support.apple.com/en-us/HT207587
or
on your Mac you can edit video with Quick Time:
QuickTime Player User Guide
https://support.apple.com/en-au/guide/quicktime-player/welcome/mac
or
A wide range of third-party camcorders and digital still cameras are compatible with iMovie on your Mac.
iMovie for macOS supported cameras
https://support.apple.com/en-us/HT204202
iMovie support, user guides etc.
https://support.apple.com/imovie
Hope this helps you :)