When you create a folder you need to create its structure (add fields to records).
You can meanwhile create groups to place your fields there.
You can add as many groups and fields as you need.
In order to add a field group, scroll down and hit "ADD GROUP" button:
Having grouped the fields (ex. Contacts; Socials; Other contacts etc) you will then be able to go to the record and hide some groups you do not need to concentrate on. If you have many fields you will need to scroll down all the time. This way you will hide the ones you currently do not need and proceed working with the record: