Biil, your a long way from the CG and there are several ways to do it. On your plans there should be a datum line that you will make measurements from. It's often mentioned in the instructions. Find it and mark it on your fuse, you will need it later. Using a pully with a couple of lines and a plumb bob is just one way to find the CG. My last shop I had a pully set up permently but also use a CG machine, both home made and bought from Great Planes. When it's time you can look it all up but you have a while. You could read about how to do it in several places.
Also look up incidence, it will be mentioned a lot when you are trying to trim your plane. It's nice to know in advance what these things are. There is a sticky with RC terms used in one of the forums, I think beginners? Also look at Getting Airborn, ask Ken about it. Tells you most everything you need to know.