You cannot delete Safari. If you cannot get out of Safari at all - the screen is frozen on you - reboot the iPad.
Reboot the iPad by holding down on the sleep and home buttons at the same time for about 10-15 seconds until the Apple Logo appears - ignore the red slider if it appears on the screen - let go of the buttons. Let the iPad start up.
Now clear Safari and restart your iPad. Go to Settings>Safari>Cookies and Data. Restart the iPad. Restart the iPad by holding down on the sleep button until the red slider appears and then slide to shut off. To power up hold the sleep button until the Apple logo appears and let go of the button.
Hopefully you will be good to go.