I am making a Call of Duty type game, how can I make the people settings just like call of duty?

You're actually asking several separate questions here. Well, I've got good news and bad news.

The bad news:

• You're asking how to make people which visually resemble the people in CoD. These are called models. There are many different free, and expensive, modelling programs out there. Blender is a good one to start with. However, creating art resembing CoD's is a vast topic, and, well, not to be discouraging, but somebody new to game development stands a low chance of creating artwork resembling CoD's in quality. Still, you can give it a shot.
• Unknowingly, you're also asking how to create the scripts that control the player character. (e.g. make him move forward when you press forward, shoot when you press shoot, etc.) This is a quite complicated topic of its own right, and one that has been addressed many times in this community.
• You're asking how create non-player characters. (I assume that's what you mean by CPUs). This is another enormous topic that requires a lot of time and devotion to complete. If you want to see just how complicated, just Google "game ai".

The good news:

There are many tutorials written solely for the purpose of aiding beginners to learn how to create projects such as these. For modeling tutorials, have a look at Blender's Tutorial Page. For scripting tutorials, I highly suggest that you take a look at both the Lerpz Platformer tutorial, and the First Person Shooter tutorial. Together, these tutorials should give you a good headstart into Unity. Good luck with your game, and if at first it seems impossible, just keep at it. :)

well im working on one and its join well its called t4f shon of war look it up ina year or 2