I downloaded turbotax deluxe on my HP computer. Trying to open turbotax deluxe now but is saying the app I am trying to install isn't a microsoft verified app.

TurboTax is not from the Microsoft store.  You need to change your computer settings to allow it to install.  This link should help you to take care of the problem.  [FIXED] The App you're trying to Install isn't a Microsoft Verified App - Appuals.com