How to change my camera settings from Manual Focus for Auto Focus?

I set my Nikon D5000 to Manual Focus in my settings on accident. Now I don't know how to get off of it.

This should be in the Camera Manual that you really should read…

This is of course is covered in your instruction book, but on the chance you have a book converted from Chinese, I would suggest you look on either side of the lens itself. You should find an "A" or "M", which indicates manual focus or auto focus.

Usually you can look in the manual you got with your camera or in your camera setting or there's a switch on your camer lense MF/AF for manual focus or auto focus

Another dSLR wasted on the wrong hands. The Manual. It can save us from answering queries like this.

AF.S, AF. C, M (autofocus-single, autofocus-continuous, manual) Gosh! I think you bought into the wrong brand. Nikonians aren't supposed to be technically challenged.

The D5000 does not have an autofocus motor in the body. Therefore the camera body does not have an AF/M switch. If the lens is AF-S, then the lens will have a switch to select auto or manual focus, If the lens is not AF-S, then it will always be manual focus with the D5000. Bodies that have a built in motor (e.g. The D90) do have a switch, because there are non-AF-S lenses that can autofocus or not depending on the setting of the camera body's switch.