My scene pane is just dark gray. I don’t see any axes. How do I turn them on
The axes (plural of axis 
will only show up if you have something selected in your hierarchy and you have either the move, rotate or scale manipulators selected (press W, E or R to switch between them).
Edit: Ohh, you mean the gridlines. Untoggle the small “landscape”-icon (Game Overlay) next to the icon of a sun on the menu at the top of your scene window, and those should appear.