Set up the project: Create a new directory for your project and initialize it with a package.json file.

Create HTML and CSS files: Create an index.html file for the app's layout and a styles.css file for styling the HTML elements.

Create a navigation bar: Create a navigation bar using HTML and CSS to display links to different pages of the app.

Add routing: Use the built-in window.location object and the history API to change the content of the main element based on the current URL.

Create a form: Create a form component using React and add validation using JavaScript. Display error messages for each invalid field.

Use toaster notifications: Create a custom notification component using React. The component should accept a message and a type as props and display them in a toaster notification.

Use popups: Create a custom popup component using React. The component should accept a title, content, and actions as props and display them in a popup window.

Add functionality: Add functionality to the app, such as displaying menu items, ordering food, viewing restaurant information, etc. Use React state and props to manage the app's data and update the UI accordingly.

Test the app: Test the app thoroughly to ensure that all features work as expected.