i have an iphone SE 1st generation, and it is saying "iPhone disabled connect to itunes" i did that and still got nothing. so how can i factory reset it?

If you forgot the passcode on your iPhone, or your iPhone is disabled or unavailable -

Click on the link for instructions on how to reset your passcode without a computer if you have iOS 15.2 or higher.

If you see an iPhone or iPad unavailable message or Security Lockout screen - Apple Support

Click on the link for instructions on how to reset your passcode using a computer.

If you forgot your iPhone passcode - Apple Support

Did whoever gave you the iPhone also tell you the Apple ID and Apple ID Password used to set up the device. Without it, you won't get anywhere on a disabled iPhone someone "gave" you. And without the original purchase receipt, which clearly shows the iPhone serial number, Apple won't help you.