Having trouble with Prusa i3 set up

Hi, I have recently finished putting together my prusa i3 that I bought from Replikeo. Ive had little support from them, and very bad instructions, so help from so people that know 3d printers well would be awesome. So far ive had the following problems:
-z axis will not move after connecting proximity sensor (echo: endstops hit)
-extruder drive hasnt yet moved when tell it to in repetier
-also, i really need help calibrating this whole printer. It doesnt yet know where the 0,0 it and when i tell the axis's to go home the all just move and crash into the endstops, and the endstops do not stop them
i will post my marlin config-h below for you guys to look at.
(also- my printer is meant to be a dual extruder, but replikeo did not sent one of the bearings needed to finish the second extruder drive, so it has two working extruders but only one actually works)

*** EDIT *** - sorry, deleted the wron thread, so edited this one ...

Edited 1 time(s). Last edit at 03/07/2016 04:14PM by VDX.

Can you connect to the printer from your computer and send it commands from a host software? If so, the first thing to do is to check that the endstops are connected to the connectors they are supposed to be connected to, and operate in the correct sense. You can do this by sending m119 to the printer and looking at the response. Make sure none of the switches are being touches by the carriages and you should get responses indicating that all the endstops are open or not triggered. Now hold down the x-axis endstop and send m119 again. This time only the x axis should report triggered. If It reports triggered when it should be open then you need to change the XXX_ENDSTOP_INVERTING value for the appropriate endstop. If the wrong endstop changes then you need to alter your configuration to match the physically installed endstops, or changing the wiring so that the endstop is connected to the right pins. You have homing defined to go to an X max endstop (the right hand side of the printers as viewed from the front), y-min (the back of the printer) and z min (the bottom). Once you have the x axis endstop working correctly repeat for y and z.