Someone who didn’t make Kiddush Friday night must make Kiddush by day. Can such a person drink before davening in the morning or must they make kiddush even before this?
It is not permitted to eat or drink before kiddush.
Although for kiddush in the day, it is permitted to drink water before kiddush, this is only true before davening, when one is not yet obligated in kiddush.
For somebody who did not make kiddush the previous night, the obligation of kiddush is immediately incumbent, and one may not eat or drink before making kiddush.