I want to know the ruling regarding Janabat. Can I eat breakfast in the morning without ghusl e janabat? And also tell me is there a sin sleeping in janabat state at night? Do I have to perform ghusl and then sleep? Kindly guide me accordingly.

It is makrooh to eat and sleep for someone in the state of janabat. But make sure do ghusl before Fajr and don’t miss it.
Still better to do ghusl before you sleep.