How do I remove the ability for users to set up their own dashboard?

If you want to make sure everyone sees the same dashboard, you can set up Home control to App manager. To do so:

1. From your user profile image, go to Application settings > Application.
2. Go to the Governance tab.
   
3. Scroll down to Home control and choose App manager. Scroll down and click Save.

You can also configure the app's Home default layout from this section. To do so: 

1. From the Home control option, click Configure home default. 

The Home default takes effect when Home control is set to User. This is what a new user sees when logging in for the first time. After this, users can customize their own home dashboard with layout and tiles of their choice.

Changes to the Home default are automatically saved but only applied to new employees. If you want to apply these changes to all employees' home, you can overwrite home dashboard settings for all users.