The only place in the app where users have access and can change the data, is their dedicated User page.
It's also one of the three options of data input.
The administrators have under control specifics of this page in the User info tab in Settings; they determine what fields will be visible for them and if their content can be changed.
There are several fields you can manage, the following screenshot captures just a part of them:
As you can see, every field has several options:
Predefined values for the field guiding users towards a better choice
- Visibility for the admin and user view
Custom name (available for Custom fields; renaming them will make things easier for you and users)
Advanced Field mapping for G Suite synchronization purposes