Help with basics on using the Arduino Uno with 1 single drone motor

I have everything set up: battery -to- ESC -to- Arduino Uno -AND- ESC -to- only just 1 drone motor (It's not for a quadcopter so don't worry about that)

AND I am not connecting it to a remote, I want to turn it off and on and adjust the speed through my desktop is all.

So the next step is plugging the Arduino Uno into my desktop. Then what?

I know the answer is there if I just look, but I know it'll be easier to just ask. Thanks

You will need code on the Arduino to arm and control the ESC and code to read the serial port and parse the control data. Then you need a way to enter the control data on the PC and transmit, via Serial, to the Arduino (serial monitor, for instance).

The servo library for ESC control. Serial input basics.