In Settings > People > Employee form setup
you can define which fields are visible on your employees' personal profiles, and what information managers can enter when they create or edit an employee.
In each of the three first tabs, you can add, remove or reorder fields as you like.
However, we recommend that you don't add too many fields in the "Create” tab. When a manager creates a new employee, the process should be as simple and smooth as possible. The rest of the information can be added later, or you can ask your employees to fill it out themselves.
You can also make your own user defined fields to add to the sections. See how to do so here.
Remember to save before leaving the page.