How can we avoid constant changes, etc with passwords on our MACs and keep them protected?

Hello Graciegirl701,

Thank you for reaching out to Apple Support Communities. We are happy to help you!

We understand that you would like some additional information regarding the passwords on your Mac, as well as, how to keep them protected.

We have provided you with a few different forms of information:

iCloud Keychain is a great feature to keep your passwords safe, but also have them saved on your device to avoid having to input them each time.

Set up iCloud Keychain

How to find saved passwords on your Mac

Also, you have the option to add an added layer of security to the information on your Mac by encrypting the information:

Use FileVault to encrypt the startup disk on your Mac

About encrypted storage on your new Mac

We hope this finds you well!

Cheers!