i have factory reset the iphone i purchaced second hand. now i can not access it as it says the phone is linked to an apple id. how do i get past this so i can keep setting up the phone

 you need to be able to contact the previous owner to have them log out of iCloud or go to https://www.icloud.com/find/ My Phone and erase the device, then remove it from their account. If you can’t do that, the device is useless. Apple won't unlock it.

Turn off Activation Lock - Apple Support.      

See Turn off Activation Lock https://support.apple.com/en-us/HT201441. 

You acquired your device second hand from someone other than Apple or an authorized Apple reseller. The following information explains what has happened. You apparently didn't know to heed the advice given below.

"Before you buy/acquire 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."

And see: Activation Lock for iPhone, iPad, and iPod touch https://support.apple.com/en-us/HT201365.

See this heading Check for Activation Lock before you buy/acquire a device from someone else.

The presence of activation lock means that we can't help you. We are not authorized to remove the activation lock from any device. And, under your circumstances, Apple support will not remove it since you cannot provide proof of ownership that they will consider to be sufficient. To remove the activation lock, you would need to get help from the legal owner. Doing so undoubtedly won't be possible. And, even it contacting the legal owner is possible, they are not going to help anyone use a device that most likely was stolen form them.

The bottom line is that the device is useless to you.