what if I broke my ipad and I want to repair it. Do I need to pay if I still have warranty?

iPad damage repair costs for AppleCare+ and out-of-warranty, plus additional information, are in this Apple article:

iPad Repair - Official Apple Support

Note this small print, however:

 If the issue with your iPad was caused by severe damage from an accident or from abuse, you might have to pay the full replacement value.

If you purchased AppleCare+ with your iPad, then it's $49. They will replace the device, not try and fix it. So make sure you back it up first so you can restore your data to the replacement device.

If all you have is the normal warranty, or it's been more than a year since you purchased it, then you have no coverage. Warranties cover manufacturing flaws, not damage caused by the user.