You can put your own movies into the kindle fire. You would have to first convert any video (movie file) into mp4 file format on your computer. There are many free software that will burn movies into mp4 format. Then connect your kindle fire to your computer using a mini HDMI to USB cable. Then drag or copy your movie file inside the video folder. Disconnect your Kindle from your computer.
Then on your kindle fire go to your gallery and you should see your movies there.