Sounds as if your iPad needs a restart or a reset. First, if you can, close the Mail app (so that your homescreen is showing). Don't worry if you can't... Then, do either of the following (or both):
Restart: Hold down the power button until the power off slider appears. Slide it off. When the iPad finishes shutting down, hold down the power button again until the Apple logo appears.
Reset: Hold both the power and home buttons until the screen goes dark and the Apple logo then appears (the slide to unlock screen may or may not appear). Once the logo appears, release the buttons. After a time, your homescreen will appear. Please note that it may take some time for the Apple logo to appear or for your homescreen to appear (or both). This is normal. Eventually, the homescreen will appear.
You'd be surprised by how often these two procedures solve a lot of the hinky behavior of the iPad. Give it a try and let us know how you get on. Good luck.
Marilyn