You cannot disable fields already found on the system (such as Phone, Email, Name, etc.) but you can hide specific Custom Fields from view by unticking 'Searchable' when creating the field. If the field is not mandatory, you or attendees can also simply leave it blank.
Learn more about what you can do with Custom Fields by visiting this article.
Contact us through email or by creating a support ticket at the top of this page if you have any other questions.