I took 2nd class compartment for my journey and it was a simple experience. The train stops at major stations and you can see food vendors trying to sell you tea, coffee, eateries, cakes, sweets etc.
A word of warning:
Do not ever buy food stuff sold on the train. Most of the food are not prepared well and it is also stored in unhygienic conditions. If you are travelling by first class better take a plane rather than train. But if you want to experience the mass transport system and enjoy the crowd just get into the second class compartment and enjoy the joyride.