Muslims should visit places that are morally safe. Muslims are certainly allowed to go to a restaurant to eat what is lawful there. However, they should prefer halal restaurants to other ones. As for pubs and nightclubs, Muslims are prohibited to visit them.
Dr. Muzammil Siddiqi, president of the Fiqh Council of North America, states the following: As for pubs and nightclubs, it is haram to visit them and to sit there and consume food in those places, even if it is halal food. Muslims should avoid these places. If you happen to be in some place and cannot find any food except in a pub or a nightclub, you may go there and buy the right food and eat outside. Do not sit in the place where haram things are going on. Allah has described the believers in the Qur’an saying [Those who do not attend falsehood and when they pass near senseless things they pass by with dignity] (Al-Furqan 25:72)