The light coming through the aperture is hitting the mirror, which is located in front of the shutter, and it swings up at same time as the shutter release. The shutter speed is determining how much light is coming through the aperture according to the light source that is available. The aperture is located in the lens. You may focus the camera by looking into the lens. There will be a circle with a line going through it, and you know you are focused when the object you are looking at through the circle/line is not split in two; it is one solid object. So the image that is reflecting off of the mirror is now going to the film, and so now the image is created in the camera.
You put the film on the reel, which is a circular type object. You line the "rabbit teeth" up and put in the film. Keep the left side put and turn the right side until the whole entire film is loaded onto the reel. This process is known as reeling. Next, you take this reel and put it in the tank, which is a light proof container. You must put the reel on through the center column. After that, you put the lid onto the tank. I wasn't there to observe the following steps as well but I'm pretty sure that you take the tank, take the lid off, and put the developer into the tank. You swish it aroung for about 2 minutes, and then put it through the stop bath, which stops the developer. You also put fixer in it and swish that around as well. Since we couldn't get past the fixer due to some problem in the chemicals, we didn't do wash, photoflow, or dryer.