Hi WLK2015,
Welcome to Apple Support Communities.
It sounds like you’re running into an intermittent issue with the onscreen keyboard not appearing on your iPad Air. If you occasionally use a wireless keyboard with the iPad, the article linked below may explain why the issue is occurring.
Onscreen keyboard doesn’t appear in iOS after using a wireless keyboard - Apple Support
If you aren’t using a wireless keyboard with the iPad, try restarting or restoring the iPad.
This article will walk you through the process of restarting your iPad.
Restart or reset your iPhone, iPad, or iPod touch - Apple Support
And, you can use the article as a guide for restoring the device.
Use iTunes to restore your iOS device to factory settings - Apple Support
Cheers,
-Jason