How to Disable YouTube Search History:
If you don’t like how Google stores your YouTube search and watch history, you can How to Disable it
Go to the Google My Activity page:
Go to myactivity.google.com. If you’re not signed in, do so now.
Click “Activity controls”:
It’s on the left sidebar.
Turn off YouTube Search History:
Toggle off the blue switch, right across “YouTube Search History”.
Confirm the change:
Click PAUSE to do so.
Note that any previous YouTube search history will kept. You may want to read How to Clear Your YouTube History.