What are the conditions for interpreting dreams, and what is the ruling on taking payment for it according to Sharia, and why did God choose Yusuf to interpret them even though his father used to interpret them?

It is a condition for one who interprets dreams that he be knowledgeable in this field. It is permissible for him to take a wage for interpreting dreams and teaching their interpretation, because it is not an act of worship (qurbah). Allah the Almighty specifically bestowed upon Yusuf (peace be upon him) additional favor in dream interpretation, and "Your Lord is most knowing of whoever is in the heavens and the earth. And We have certainly preferred some of the prophets over others."