Other photography tips:

Now that you have made your pinhole camera, what do you do with it now?? Well, many sites don't include this part of the project but it is information you need. There is no transferring the image from your pinhole camera onto a jump drive and printing it from your computer. You are going to need a dark room, chemicals, a red light and developing tools. All of these supplies are available online and some local camera shops may carry them also.
Again, the films and dark room paper are LIGHT SENSITIVE. You can't pull the dark room paper or film out in any light just as you can't open the back of a camera when you have 35mm film in it.
You will probably need to play with the 'exposure times' for your pinhole also. Since the push pin makes such a small hole, you will need to lengthen the time you are pointing at an image, cover the pinhole and get back into the darkroom. (The whole time this is going on, remember to keep the large open end of the tube covered with your black cardboard disc and foil cover.)
Lastly, keep in mind that the image you are getting is going to be a negative, that is, the light areas will be dark, and the dark areas light, as well as the image being reversed!