I was recently reading the games manuel and I found a section that told me the mods and how they work. Out of the four I only found one of the mods which was world builder could anyone help me on getting the other mods which are XML, Python, and Game and AI SDK.

You are not listing mods, but only tools that allow creating mods. World builder is basically a scenario editor. XML and Python are programming languages that can be used to modify certain aspects of the game. The SDK allows even further modifications, what exactly, I am not sure and I don't care much either.

If you would like to try playing some mods, you can either try the official, included in the game (start the game, choose something like advanced -> load a mod.

If you'd like to try some fan-made mods, look here: http://forums.civfanatics.com/forumdisplay.php?f=171. You'll have to download them and install them.

I was wanting to know where to get these programs so I could make my own modifications.

As Crunch pointed out, they are the tools for modding. They are not "programs to get" somewhere. You should probably head over to the Creation & Customization section of the forums. There are quite a few sticky threads that should walk you through the process of creating a mod. And, if you have any questions after reading the sticky threads, the folks over at C&C are quite experienced and will be able to help you out.