how do i print from the ipad air2

Depends on your printer whether you can use AirPrint:

https://support.apple.com/en-us/HT201311

or some brands have apps that work with their printers (e.g., Epson).

As mentioned

Use an Air Print enabled Printer

Use a wifi printerw with either an app from the printer manufacturer

Or use a third party printing app with the wifi enabled printer

You'll need to look up your printer model to see which option works best for you