Can't schedule My Passport Ultra on iMac

My Passport is backing up all my Documents and HP Backup drive each day unnecessarily. There is no access to any scheduling or set up function anywhere that I can find. I am 70, so please use simple terms in responses. Thanks.

Welcome to the Community.

Automatic Backups on Mac OS are directly handled and controlled by Apple Time Machine. Your WD Passport Ultra will use the settings that are set for Time Machine and will not follow a secondary/independent ruleset.

For additional information related to Apple Time Machine please visit the following link:

https://support.apple.com/en-us/HT201250