The camera comes with a flex cable that must be inserted into the camera port. In order to do so, you must first lift up on the tabs.
Using the image as a guide, insert the flex cable into the port so that it's fully seated. Then push the tabs back down, locking the cable in place.
Learn how to use the picamera Python module to take pictures with your Pi.
OctoPrint is a platform designed for the Raspberry Pi that makes it possible to monitor and control your 3D printer. If you want to watch what your printer is up to remotely, you'll need a camera.