What should you know for good TypeScript code for Node.JS?

Question

JavaScript

Simple Node.JS ES6 TypeScript static web server - posting for community review as an example of my code. This is my first node project. What should be corrected and what should be read for a better understanding? What errors are immediately visible, what approach should be followed and what should be improved?
Before that, I worked with PHP, I know enough about the web :) I
plan to add interfaces, fix some types and JSDoc for them.