Quick setup

1. Download and install Node.js.
2. Open the terminal and install TypeScript globally:

   npm install -g typescript
   

3. Create a JavaScript file and add some content; let's call it index.ts:

   console.log("Hello world!");

4. Transpile your file into a JavaScript file:

   tsc index.ts
   

5. Verify that a index.js file was created at the side of the index.ts file.
6. Run your new JavaScript file with Node:

   node index.js
   

Bonus

You can use the tsc index.ts --watch command to continuously monitor your TypeScript file for changes and transpile it to JavaScript every time your .ts file is saved.