Tracing
From GeoGebra Manual
Objects can leave a trace in the Graphics View when they are moved. Use the Context Menu to switch this Trace On. Then, modify the construction so that the object whose trace you turned on changes its position and leaves a trace.
You can turn off the trace of an object by un-checking Trace On in the Context Menu. The menu item Refresh Views in the View Menu clears all trace.
Note: The trace is not permanent, it disappears e.g. on zoom. Instead of permanent trace of a point you can use Locus.
Tracing to Spreadsheet
Right-click on a Point in the Graphics View -> Trace to spreadsheet option