How to focus my Nikon d3100? - 2

I'm trying to film a video of myself showing objects. But every time I hold an object up to the camera it doesn't focus on it, how do I focus objects to the camera not manually?

It doesn't auto-focus. You'll have to focus on the area you'll be first, and then move to that area.

The dSLR was never meant to do video hence the severe lack of video control. Focus manually. There's no other way.