I don't know how to make videos. Can you even make videos on Nintendo Video? Please help.

No, you can't.

But you can with a recent firmware update that allows you to record videos in the Camera application.

You need 3DS camera, not Nintendo Video, silly!

Here's what you need to do to record videos.
1. Go to the 3DS home menu.
2. Click on the Nintendo 3DS camera app.
3. Once you are in the 3DS Camera application, the touch screen will display three buttons on the top of the screen with camera icons. The one on the left changes the camera you are using (inner single camera, outer 3D cameras). The middle button lets you take single pictures. The button on the right has an icon that looks a bit different, that one is the video camera. Tap it.
4. Now you are ready to record videos! Just click the L and R buttons on the side of your 3DS to start recording.

If you tap on the parakeet, he will tell you useful details about the 3DS video camera. I'd recommend tapping on it a lot.