Hi ScryptoNoob,
I had the same problem with the Z axis - look at the underside of the printer and check that the Z axis cable is connected and not just stuck to the bottom of the printer with tape. After you assemble the printer and put in the Z axis etc, you need to connect the stepper motor 
That’s exactly what it was. Just a minor oversight in the setup instructions lol It works now but sadly the limiter for raising the platform doesn’t function properly so it just keeps going and mashes the bed into the nozzle. 
The Z axis limit switch is operated by a large screw at the back on the RHS of the Z axis lead screw - check if that is switching the microswitch - I didn’t have to adjust mine, but yours may be out of adjustment.
To adjust the Z-offset screw, manually move the printer to within about .5 mm of the nozzle (farther than you would normally use to print), then put an ohm meter on the Z-limit switch and slowly turn the Z-offset screw until it triggers the limit switch. At this point you should be able to test the homing function without damaging the nozzle or bed.
Once that’s done, and the bed is now sitting at the height it now wants to home to, use the bed levelling knobs under the corners of the bed to raise the bed the appropriate print level with what ever you use to set the initial height (paper, post-it note, feeler guage, etc.). Do this in all 4 corners, then re-check it and repeat until you no longer need to make adjustments.
Any imperfections that remain will be taken care of by the BL-Touch.
Silly question, is BL Touch a physical sensor that I need to purchase and install? If not, will the autohome/levelling functionality work without it?
Yes it is a physical sensor. Maybe it depends on the firmware. There is firmware versions that do the baby stepping and such but do not look for a sensor. Some firmware will look for the sensor not find it and report and error.
Thank you. I definitely do not have one of those.