The "wait 24 hours" sounds like Factory Reset Protection to me.
So let's be clear: you got it from a previous owner and reset it. Had you set up your account on it before you reset it, or did you reset it before using it? If the latter then it's almost certainly the previous owner's Google account that's needed to unlock it. The trick in that case is to get the previous owner to provide the information to unlock it, then remove any Google account from it before resetting. After that it will be completely clear and you can then set up your account as you want.