The most likely reason your Ryobi Airstrike P320 will not shoot nails is due to the base of the striker being seized up due to a lack of lubrication.  This happens when the tool has been sitting unused for a long period of time (including the store shelves). 

Here's how to fix:

Tools Needed to Fix Ryobi P320 Airstrike:
3mm and 4mm hex key, or T25 and T15 bits and driver
Pliers
Oil

Step 1: Remove Battery and Nails
Step 2: Unclasp the top of the Airstrike, and remove the 2 screws.  Remove the clasp
Step 3: Remove a bolt at the bottom of the magazine and a screw on the side.  Remove the magazine
Step 4: Squirt oil down the cylinder walls that house the striker
Step 5: With pliers, gently but firmly pull straight up on the striker to lubricate the cylinder walls and the piston rings at the base of the striker.  Repeat several times
Step 6: Reassemble

Blog: https://homebatterybank.com/ryobi-airstrike-brad-nailer-fix/

Additional Longer and more Detailed Video if anything was unclear: https://youtu.be/w9-noJgnwlc