Q: How do I create a zip file to email video's?

You would right click (Control-click) the file and select "Compress."

However, it won't reduce the file's size by much, if anything, because video files are already greatly compressed.

Probably best to use a service like "Wetransfer" or "Wesendit" where you upload the file to the cloud and you email a download link to the recipient. 

With Yosemite or later you can use Mail's "Maildrop" facility to send files up to 5 GB (see; Mail Drop limits - Apple Support).

Geoff.