I only used a host program for my first axis movements. After that I have been printing with SD cards and Octoprint so this isn't my forte. That being said you need to be concerned with primarily two things:
1) Make sure the baud rate is the same of that in your firmware.
2)Make sure your computer recognizes the printer.
Both of these options are under the config menu in the host. To change baud rate use the drop down menu. To identify the printer port click "refresh ports" without the printer plugged in. Take note of ports avalible. Then plug in the printer and refresh again. That is the port of the printer.
See Arduino.cc if you cannot see the port.
Personally I would recommend using a Raspberry Pi and Octoprint or the even cheaper 12864 style lcd.
Prusa i3 Rework - Ramps 1.4 - E3d Lite6 - Full Graphic LCD Controller
