what word can express this behavior ? for example ,someone stay at home for a long time ,and don't like to go out ,what word would you use to express this behavior or this situation ?

how to express the food doesn't taste good ? for the instance ,you eat the meat ,but the meat maybe taste too salt or you don't like that taste .what could you say about this food ?

how to express the meaning of " I have no classes in afternoon ". I will be appreciated ,if you could give me some formal and informal expressions of this meaning .