How do i set ipad to factory settings if ipad is blocked

If its locked to iCloud you won't be able to use it at all. That is called Activation Lock, its an anti-theft mechanism and it cannot be bypassed in any way. Return it to where you bought it and demand a refund.

You can attempt to restore it using a computer (Mac or PC) and hope its not Activation Locked.

Follow the steps here: ➡️ If you forgot your iPad passcode or your iPad is disabled - Apple Support

If the iPad disabled or Activation Locked, unless you can independently obtain assistance from the previous owner, the iPad is (and will remain) useless to you.

Here are the Apple support pages that outline the Activation Lock - and the only mechanisms by which it can be turned off:

Activation Lock for iPhone, iPad, and iPod touch - Apple Support

Turn off Activation Lock – Apple Support

As you will discover, unless you are the owner of the AppleID that was last used to activate the device, you’ll not be able to defeat or bypass the Activation Lock. With documentary evidence that you are the original owner (such as sales receipt showing the serial number), Apple may be prepared to assist - otherwise they and nobody here will be able to help you.

Here is what Apple suggests when purchasing a previously used device:

Check for Activation Lock before you buy a device from someone else

Before you buy an iPhone, iPad, or iPod touch, from someone other than Apple or an authorized Apple reseller, make sure that the device is erased and no longer linked to the previous owner’s account. Follow these steps to check if the device is ready to use: 

1. Turn on and unlock the device. 
2. If the passcode lock screen or the Home screen appears, the device hasn't been erased. Ask the seller to completely erase the device by going to Settings > General > Reset > Erase All Content and Settings. Don't take ownership of any used iPhone, iPad, or iPod touch until it's been erased.
3. Begin the device setup process.
4. If you're asked for the previous owner’s Apple ID and password, the device is still linked to their account. Hand the device back to the seller and ask them to enter their password. If the previous owner isn't present, contact them as soon as possible and ask them to use a browser to remove the device from their account. Don't take ownership of any used iPhone, iPad, or iPod touch until it has been removed from the previous owner’s account.

You will know that a device is ready for you to use when you're asked to "Set up your iPhone," “Set up your iPad," or “Set up your iPod” the first time you turn it on.

Only the person whose AppleID and passcode were used

to initiate the Activation Lock can remove it.

Return the iPad for a refund, if you can. Otherwise,

recycle it responsibly.

There is no workaround for the security features of Activation Lock.

Here is a link to Apple's page about Activation Lock:

Activation Lock page: https://al-support.apple.com/#/getsupport