If you work primarily in one Judicial District, you can set that district to automatically pre-fill each time you create a new case appointment. This saves a step during case creation, but you can always override this default, pre-filled district while creating any case by simply changing the district during case creation.
To set up your preferred district, navigate to User Settings > General Settings on the left side menu in CARES. Scroll to the bottom of this screen to find "My Default Judicial District." Click under that heading to open a drop-down menu and choose your desired district from that menu. Scroll to the top and click Save on the screen to save your settings:
Now the selected district will automatically pre-fill each time you create a new case appointment, though you can always change districts during case creation. You can return to update this preference in the future. If you need to change back to having no default, pre-filled district during case creation, simply repeat the steps above, but change the drop-down menu from a specific district to the blank entry at the top of the menu (i.e. no district).