I want to create a page My Self and add React Component

I want to create a page My Self as an example and a react component. However, I could not connect that page as a React component to the React Router.

Further, I could not find out About Us and Contact Us pages.

I am new to SilverStripe

Showing what you tried so far and what part of your code fails would help to understand what you are asking.

About Us and Contact Us in default Silverstripe CMS are Page type, so the relevant code is in Page.php (for the model) and PageController.php (for the controller).

You don’t need a page type for each page, you need it whenever the overall layout changes significantly. Please, check this tutorial for more details on page types.