Go to your Google Account at myactivity.google.com
Sign in if prompted
Click Delete activity by
Select a time range
Choose Search
Click Delete
To delete individual searches, find the item in My Activity
Click the three dots next to the item
Click Delete
To stop saving future searches, go to Activity controls
Turn off Web & App Activity
On mobile, open the Google app
Tap your profile picture
Tap Search history
Tap Delete
Choose a time range or specific items
Confirm deletion