What are you trying to connect to? I ask because some are under the impression Bluetooth will connect to another wifi device, like iPod.
Bluetooth should connect to input device (Apple keyboard) or output device (speakers, headphones).
Make sure airplane mode is off, Bluetooth is on and follow directions for the Bluetooth device and set up in settings.
If problem continues, try resetting iPad.
In settings, general, reset, reset settings. This will not effect data.
You can have Airplane mode on. It doesn't matter, you just need to run on Bluetooth.
To repeat though, Bluetooth on iOS devices is used to connect keyboards, speakers, earphones and a few other uses. It is not normally used to pair two iOS devices.
Let us know what you want to accomplish and someone here will help you learn the way to get it done.