To delete an email address from your iPad, go to Settings -> Mail and contacts then click on the email address you want to delete. There should be a choice below that says Delete!
Good luck!
You don't need a computer to unlock the device, but if you bought it used and there is an activation lock on it, then you need to take it back and get a different device or make them get the previous owners credentials to unlock it,
Your screen has been damaged. This may be because you dropped or because of something similar to this. The only fix to this is either to bring to a specialist who you can pay to fix the screen, or you will have to buy a new one.
Hmm. I used to love vine and be on it everyday so i think i know this, I believe that their is no blocklist in settings so i think you just have to go to the persons profile that you would like to unblock and act like you are trying to block them. There should be an unblock button on their profile where the follow button should be.
It's quite unpractivcal to try to help you to set up an iPad through a Q/A site.like this
Look for help at
iPad Help: 8 Lessons for Beginners
http://ipad.about.com/od/iPad-Tutorials/tp/iPad-Lessons-For-Beginners.htm
Also might help you to do a ggogle search for
ipad for Dummies
you'll get some websites where you can buy books for iPad beginners
you can not download google play store app because google app store application have different extension then iphone apple app store for google app store application extension : .apk for iphone app store entension : .ipa so you cannot download a apple store app on i devices