You are right about the "ground" . The remote glow plug is adapter is what it is called. Since the threads of the glow plug are connected or screwed into the head of the engine, the engine and anything metal touching it will act as the negative side circuit. If your glow starter is the portable kind, you just connect it to the remote plug and it will heat the element on the real glow plug assuming it is good.

Now for your panel question, You should have a number of bannana female connectors if it is a standard power panel. Some power a starter like yours, another is either a 12 volt and 6 volt fuel pump with on/off switch and direction switch, which changes the fuel pump to either put fuel in the tank or suck it out. Below the meter is another set of bannana sockets that you can plug in a glow plug initer that runs off your 12v battery. The pot or dial controls the current to your glow plug. If you have one of those glow plug igniter plug it in there and plug it into the remote. Be sure to turn it down all the way before plugging it in. THen turn it up to the green area and that will heat the element.

I say all of this just to familiarize you with the panel and remote glow starter. But I strongly encourage you to find someone to help you get started. Find the local flying field and get some help from a heli flyer. If not you are bound to get frustrated. I suspect crashes, will be common if no help. These things can be a bit pricey to repair. GOod luck.