Building a Z plot and TTL signal



So I bought the XY Plotter pretty much my first foray into Machine building and coding with Arduino. It took a bit of time fumbled around until I got it working.
So I can use the GCodeParser and the GRemoteFull,.

So I want to advance this project a bit further and add a proper Z component to the system. I can see that there are spare ports on the Orion board and I have stopped using the Servo function pencil down and up function (for now) so I was hoping to swap this out with a proper Z carriage that can change the height of the stage and pointer.
Further to this when the X, Y and Z movements are complete I want to be able to reach a position and send a TTL pulse and wait for a 300seconds before continuing on with the movement? Does anyone know how to do this? Could point me in the right direction.

I’ve bought an identical stepper motor and a Me Stepper driver but despite connecting to the different ports I can’t even get power to go through to it?

Thanks for reading