What is the ruling on training in a hotel where alcohol is sold and dancers are brought in, while avoiding mixing with these prohibited things and limiting oneself to cooking? And is the money and food provided by the hotel owner unlawful, especially since she is the cousin and claims that she does not profit from alcohol and has other sources of income?

It is obligatory to leave work in a place where Allah's prohibitions are violated, as it constitutes assisting in sin and exposing oneself to temptation. There is no objection to taking the money paid by the hotel owner, as her wealth is mixed. It is obligatory to advise your cousin, the hotel owner, to fear Allah and purify her hotel from unlawful things, as it is not permissible for her to engage in such activities. It is forbidden to sell alcohol to a Muslim or a disbeliever.