There are two ways creating mobile users: Manual creation and Bulk upload. You should use bulk upload tool if:
Go to Users screen and select "New Mobile Worker". Two steps are included in this manual creation process:
In sheet users, username and password are two required columns. All else are optional (phone-number would also be required if you are using CommCare Supply SMS instead of mobile app).
Fill in the other fields as necessary and note that a user can be assigned a location (Supply Point) through the location columns. A user can be assigned multiple locations if desired, though for each additional location a new column must be added in excel (location_code 2, etc.)
Once you are done editing the download, upload it and if there are no errors, you will be shown a screen like the image below.
On the Mobile Workers page, selecting that worker's user name will bring you to Edit Mobile Workers. The Locations tab on this screen will show you what Locations (or Supply Points) are assigned to this user. Here, you can also see that user's primary location and any associated Program.