We will learn TypeScript by taking small incremental steps. We are learning this language becuase Angular 2 is being built using TypeScript. We will use a combination of TypeScript and Angular 2 to build web apps. You can also start learning Angular 2 from: https://github.com/panacloud/learn-angular2
Learn React using TypeScript: https://github.com/panacloud/learn-react
You can also learn Node.js/Express using TypeScript from: https://github.com/panacloud/learn-typed-express