You learn to read what the compiler tells you. A string assigned to a number gives a first type error, and you read its file, line, column and error code. You see that a failing check exits with a non-zero code, so scripts can stop on it. Strict mode, on by default in TypeScript 7, flags a parameter with no type and a value that might be null. Finally you watch the types disappear: the JavaScript output keeps the code and drops every annotation.

You move from single files to configured projects. npx tsc --init writes a tsconfig.json with strict settings already on, and you see what each one catches. You compile one file inside a configured project, find out why the compiler refuses, skip the configuration on purpose, and then build the whole project into a dist folder. The module closes with the settings older tutorials still recommend, such as the ES5 target and classic module resolution, and the errors TypeScript 7 gives.

You shorten the loop between writing code and finding mistakes. A language server gives your editor hovers and errors as you type, shown in VS Code with the TypeScript 7 extension and in Neovim. Watch mode recompiles on every save, and source maps make a runtime error point at the TypeScript line instead of the JavaScript. Then you build a small typed unit converter from its brief, with strict mode on, and finish with the contract check that proves it does what the brief asks.