Right-clicking a marker in the timeline opens the marker context menu:

Locate to Here Move the playhead to this marker's position.
Play from Here start playback from this marker's position.
Move Mark to Playhead Move this marker to the current playhead position.
Create Range to Next Marker Create a range marker between this location and the next one along on the timeline.
Hide Hide this marker from the view. It can be made visible again from the Window > Locations window or the Ranges & Marks list.
Rename Change the name of the marker.
Lock If this is ticked, it will be impossible to drag the marker's position; useful if you want to prevent accidental movements.
Remove Removes the marker.

There are also a few options in Transport > Active Mark. These options apply to the currently selected location marker, and move it to a nearby region boundary, region sync point, or to the playhead or mouse.