Primary features

The most common and relevant features you show users are called the primary features of progressive disclosure. The initial disclosure level can't be too complicated, confusing, or include too many options — otherwise, users will stumble on the very first steps of acquaintance with an interface.

How do you decide what information the initial level of progressive disclosure should contain? Don't assume you know your users down to the tips of their fingers. The most rational solution is to rely on research data. If it's a new product, analyze the findings of user research (using interviews, surveys, field studies, card sorting, etc.) to understand users' needs and priorities. If it's an existing product, look at the website analytics or conduct observational usability testing to get more quality data about why users prefer specific options/features over others.