A reactive login form with real validation, visible errors, and a button that cannot be pressed twice.
Submitting empty shows a message per field, and the button disables while it runs.
Published in full, before you start — every point is one of these and there is nothing else.
Standalone components declare what they need instead of belonging to an NgModule, and inject() gets a dependency without a constructor parameter — together they are most of what changed in modern Angular.
A reactive form is a typed object you build in code and bind to the template, so validation rules live with the model rather than scattered through markup.
The @if and @for blocks replaced *ngIf and *ngFor, and the track expression is what stops Angular rebuilding every row when one of them changes.
Anything that talks to a network can be slow or fail; a screen with no loading state and no error state is a screen that looks broken the first time the wifi drops.
A type is a note to your future self that the compiler checks — annotating what goes in and what comes out is where most of the value is, before any advanced feature.