Hiding projects with no assignments is as simple as applying a filter.

• On the Gantt page, click the funnel icon located in the top-left corner.
• Select Hide Empty Projects, then select True.
• Apply the filter by clicking the blue checkmark.

The process is the same for hiding people without assignments. 

• First, select the People tab to view your resources.
• Click the funnel icon, select Hide Empty People, then True.
• Click the blue checkmark to apply the filter.