You can create new point features evenly spaced
along a selected area and line features by right clicking and selecting
the Advanced Feature Creation
submenu option Create Point Features Spaced Along Selected Feature(s).
This will present a Sample Spacing Setup dialog (below) allowing you to
specify the spacing to use, then create new point features at the specified
interval along the line.
Spacing options include Fixed Number or Fixed Distance for the selected Area or Line Feature.