Getting started.. finished printing and putting the machine together.. now what?

SOO Ive taken a break. i got my machine put together probably 3 months ago and just haven’t had time to mess around with it. I’m about done with wiring but have a few questions. for example. how does the machine set 0 0 coordinates, how do i set the correct stop height, how do i make sure prints start in the correct location… i guess my big concern is now i have this machine, how do i make best use of it and get quality prints. I have some things I’m interesting in making (cutting parts in acrylic) but i want to make sure when i hit print its not going to land in the center of my material and ruin the whole thing. i guess maybe I’m just missing the final pieces of the build. I currently have repeiter host installed and i can manually control the machine with this… i just need some motivation to finish and get this thing up and running.

heres some photos at it sits today.

Pretty sure this answers all those questions.