Can Nikon 8700 take videos?
Can my Nikon camera, I believe it's a "Cool Pix Nikon 8700"
If it can, can you tell me how to take a video?
Look on the mode dial. If there's a movie/video symbol, just set camera to it and start taking videos but as I know 8700 is a bit too old (though very capable camera in those days) but it does offer Movie -- TV movie (30 fps; with audio), Small movie (15 fps; with audio), or Sepia movie (5 fps; with audio), or Time-lapse movie (30 fps; without audio)
Page 49 in your manual shows it can record VGA (640x480) video, which are pretty ancient by today's standards.
Here is a link to your manual: