my iPad pro is brand new and I shut it down completely and it won’t restart

Connect your iPad to its Power Adapter and allow your iPad to charge for at least an hour. Whilst still connected to the Power Adapter:

• On an iPad with a Home button: Press and hold the top button and the Home button at the same time. When the Apple logo appears, release both buttons.
• On other iPad models: Press and quickly release the volume up button, press and quickly release the volume down button, then press and hold the top button. When the Apple logo appears, release the button.

Note: If iPad still doesn’t turn on, or if it gets stuck during start up, see the Apple Support article If your iPhone, iPad, or iPod touch won’t turn on or is frozen.

Read and follow the article linked above.