No, the link that I posted is not about Apple Watch. It is about Activation Lock for all iOS devices, including of course the iPhone, through the Find my iPhone feature. Please read it carefully and in full and you will know that there is nothing you can do.
Again, I repeat, the Apple ID you are trying to use is NOT yours. Therefore, you cannot use it anywhere. Your iPhone is useless because it cannot be activated without the Apple ID and Password to which it is locked. There is no solution other than finding the rightful owner of the Apple ID and having him remove the iPhone from his Apple ID. Then, and only then, you can create your own Apple ID and activate the iPhone with it.
If you cannot reach that owner, then you have an expensive paperweight as you will never be able to activate that iPhone until the rightful owner removes it from his Apple ID. I hope it is now clear to you.