The DJI Simulator is not compatible with the Mavic Pro remote controller. Back when it was released, I was able to connect my Mavic Pro remote controller like this. I don’t know if that still works now.
Even if you do manage to get your remote controller connected, you’ll need to be running a pretty high-end computer to run the DJI Simulator without any issues. See the required and recommended computer specs here:
If you’re not able to get the DJI Simulator running, you can also use the simulator in DJI GO or the DJI Assistant 2 application. I’ve tried all 3 simulators and I don’t think the DJI Simulator is any better than the simulator in DJI GO or the DJI Assistant 2 application. And flying outside in a wide open location that’s free of all obstacles is 10 times better than any of the simulators.