Hi! Are you actually using PX4 or ArduCopter? I’m asking because this forum is for PX4 but given you are using MissionPlanner it might be that you’re using ArduCopter in which case users in the ardupilot forums are more likely to be able to help you.
As a novice, I would like to start with the setup being very simple. A Desertrotor GCS with Qgroundcontrol, a laptop with Jmavsim, no transmitter, no receiver, no pixhawk. I want to connect the GCS to the laptop using cable and simulate a flight. Is it possible?
I don’t know what Desertrotor GCS is but generally it sounds feasible if you plug the things together and figure out the missing pieces. That’s assuming you can program and understand these software pieces.