Open your Google Account
Go to Data & privacy
Under History settings, select Web & App Activity
Click Manage all Web & App Activity
Choose Delete
Select Delete today, Delete custom range, or Delete all time
Confirm deletion
Repeat for Location History if needed
Repeat for YouTube History if needed
Turn off Web & App Activity if you do not want future history saved
Turn off Location History if you do not want future location tracking
Turn off YouTube History if you do not want future watch and search history saved