How can i start Simulator or how can i get Simulator?
uVision Project / Options For Target, Debug tab. See "Use Simulator" in the upper right. Then Select Debug / Start Debug Session.
You obviously need to read the uVision Getting Started Guide - you can find it in the 'Books' window, or on the 'Help' menu. You should work through the example projects in it - they guide you through the whole process of creating a project, building it, running it in the simulator, and debugging it in the target. This will give you a proper introduction to the tools and how to use them.