Does Mach 3 still ship with the road runner outline to practice on? Or has that long gone ?

If you want to go back to basics then another idea is:

Manually position your cutter above a scrap piece of wood, say towards the lower left corner and zero your X and Y DROs on the Mach screen.
Then slowly plunge down into the surface say 1 mm with the router running
Then set your feedrate override to 5% on the screen setting (slow it down)
Then in the MDI window type: G0 X20
This will slowly machine a 20mm long line in your part in the X direction
You can complete a small square with
G0 Y20
G0 X0
G0 Y0
(Return after each line) (The 0 is a zero not oh)
This is just saying Goto X or Y position on the part.
Then raise the Z and stop the spindle.

I’ve left out the F word (not that one!) to keep it simple.
Your first square shape (engraving)! Repeat with similar commands to cut things.

Bored of typing commands? Then move onto Doddys idea and draw the shape in CAD or CAM and let the software create the gcode.

You can view gcode in any text editor so draw a square in CAM and look at the code. It will create lots of setup fluff but you should be able to see the actual cutting bits in there now you know what to look for. You can google gcode list and see what each command does. There are M commands as well to start and stop things and F for feedrate and so on. There are commands for arcs and things called canned cycles and so on but leave those for another day. You can of course leave all the to the CAM software.


P.s. Hover over the estop at all times when test cutting !