For any entry, you need to indicate the type of entry. The type of entry is defined by the value you select from the Category drop list.
Because this is the first entry being added to the timesheet, the row will default to an entry category of “Project”. Going forward, the Category field will default to the value you selected for the previous entry. Other category types include Portfolio and Administration - you may or may not see these options depending on your organization’s settings.
Since this tutorial is about entering project time, go ahead and leave it.