I’ve heard some people mention that you cannot make wudu if your hair or feet are wet beforehand, but don’t know if this opinion is authentic
2 Answers
There is no such restriction you can do wudu in the shower and you can do wudu if your hair or feet are wet beforehand.
Not all your head nor all your feet must be dry when wipe on them in Wudhu. Just part of the front part of the head, and one or more figures must be dry. The wiping must affect that front part of the head and one or more fingers. The affect is not transfer the wetness from the hand to the wiped areas.
Wassalam.