I bought A phone but iT say iT got iCloud Lock what can i do i dont know logging on stuf

Activation Lock Problem

If you purchased the device second-hand, then it is useless without the Apple ID and password to which it is locked. If you don't have it, can't remember it or cannot get it, then the device is useless to you. Try to get your money refunded, if you can, or take it to an Apple store for an exchange provided they will help you. If you are the original owner, then take the device, a copy of your purchase receipt and identity proof to an Apple retailer where they may be able to assist you. For a deceased owner, you will need a certified copy of the Death Certificate, the device, proof of inheritance and proof of your identity. Take all to your local Apple Store for help. Note: there is no guarantee that anyone can gain access to the device.

     Find My iPhone Activation Lock

     If you can't activate your iPhone - Apple Support

     Activation Lock - Turn off Find My iPhone

If you have an Apple Watch please see: About Activation Lock on your Apple Watch - Apple Support.

If it has an iCloud lock, the phone is useless unless you can get the previous owner to remove it from their account. Return it for a refund if you can.