How can I find Apps on my new MacBook?

For a tutorial on how to use the Mac App Store, review this Support Article:

Download apps from the App Store on your Mac - Apple Support

After the app is downloaded it is placed in your Applications folder.

Are you asking where on your Mac you would find the applications loaded on it? If so, they should be in the Applications folder. Press control-space to bring up the search bar. Type in "Applications".