Blender doesn't give you a quick way to jump to timeline markers by keyboard. Marker Shortcuts is a lightweight addon that lets you assign custom shortcut strings to your markers and jump to them in two keystrokes.
Jumping to a marker takes two steps:
Example: Trigger modal state with Shift+M, then rapidly type 3 to jump to my "End" Marker which shortcut has been set to 3.

To assign a shortcut to a desired marker, either go to:

Blender's keymap system is powerful but fragile, so dealing with a lot of Markers can increase the chance to mess up your keyconfig. Also, the modal listener lets you write complex full strings shortcuts:
10Seq10Start1., 2., 3.… and assigns matching numeric shortcutsIntro, Seq1, End, etcTimeline Editors Keymaps to avoid conflict between your master Trigger keymap and other operators, but as its name suggests, it has the disadvantage to work only in the context of the NLA, Graph, Sequencer and Dopesheet Editors.This extension does not require special permissions.