Open Google Chrome or any browser
Go to Google and search for the video you want
Open the page where the video is hosted
Check whether the site provides a download button
If a download button exists, click it
If the video is on YouTube, use the YouTube app or YouTube Premium for offline viewing
If the video is your own file in Google Drive, open the file and click the download icon
If the video is publicly downloadable, right-click the video and choose Save video as
If the video is embedded on a website, look for a direct download link on that site
Use only legal and authorized download methods
Avoid downloading copyrighted videos without permission