Videos created during a Zoom event can be easily trimmed to remove before and after meeting conversations. They can then be shared through Zoom Cloud, Google Drive or Echo360.
In the Zoom Cloud
If your recording was saved to the Zoom cloud and you intend to share it from there, you can "set playback range". This doesn't edit the video, but limits what a viewer will see. The original recording is not affected. If it is downloaded, the whole video is saved. More information is available on the Zoom website.
On Your Local Computer
If your recording was saved to the Zoom cloud, download it to your local computer. To do this log into your Zoom account, from the left side menu navigate to the "Recordings" page, press the "More" button next to the appropriate meeting and select "Download".
The simplest tool to trim videos is the Photos program provided with Windows 10. Trimming is a straightforward function. Learn about this at How-To Geek.
The best tool is the iMovie program on all Mac systems. Apple provides great instructions on how this is done.