I might be able to help you with how to meter for the film. Generally you can figure that your shutter speed is going to be around 180 degrees. The most you can be off is going to be 30 degrees in either direction which isn't that much really.
So use 180 degrees as a default, and also add 1/2 of an f-stop to make up for the light that gets split off to the viewfinder. Now based on that info, if you want to experiment with one cartridge of film, zoom in to the area you want proper exposure on and see what your reading is. Either cross compare that with an external light meter, or simply use the zoom in technique, lock the exposure, then zoom out to shot you want, and see how far off you are. If you discover that you are consisently under or overexposed on every shot, then you make an f-stop "offset" adjustment and from now on you know that whatever the light meter tells you when you zoom in to add or subtract lets say one f-stop.
Once you master that concept, you can begin to increase your exposure accuracy by factoring in whether the object you are zooming into is either darker or brighter than 18% gray.