Изучите Microsoft TypeScriptУчебник по TypeScriptTypescript Бесплатный курс
TypeScript Basics
TypeScript vs JavaScript
TypeScript Syntax
TypeScript Static Types
Arrays and Tuples
TypeScript Enums
TypeScript Generics
Any and Union Types
Classes and Interfaces
Inheritance and Polymorphism
Methods and Constructors
Typing and Functions
Implicyt Typing
Object Literals
TypeScript Compiler
let, var, const ES6