To open a window and see the files on your Mac, switch to the Finder by clicking the Finder icon (pictured above) in the Dock. Switching to the Finder also reveals any Finder windows that might be hidden behind the windows of other apps. You can drag to resize windows and use the buttons to close, minimize, or maximize windows.
Hi...
Congrats on the new Mac !!
Use iTunes to re download previously purchased apps.
For syncing your iOS devices (iPad and iPhone), follow the instructions here > iOS: Syncing with iTunes
These video and text tutorials might come in handy for you > Apple - Find Out How - Mac Basics
How to use the Apple Support Commmunity forums > Apple Support Communities - Tutorials
After you familiarize yourself with how to sync your iTunes content with your devices, you may want to consider using iCloud for back up and storage. But take some time to get to know your Mac first. iCloud - Learn how to set up iCloud on all your devices
How To See App Usage On Pc
How To See App Usage On Macbook Pro
🙂