I lived in Dubai for 14 years and most ex-pats try and take their holidays in Ramadan to get away and your going there, sorry but you probably got a good deal with the travel agent because no one wants to go., they have definately had you over.
Rules are that you cannot get anything to eat or drink outside before the call to prayer at approx 7pm, you can get alcohol & food if you are staying at a 5 star or over hotel but only in your room, there is no singing/dancing/or entertainment during ramadan and everything is done sneaky and and on the sly [ ask any Brit that works there, dont ask a local or the room boy]] but should you get caught you will go straight to jail- do not pass go etc--- until Ramadan ends.
My advice is change the tickets and go to Vegas where you should have booked in the first place.I do feel sorry for you because Dubai is great but not during Ramadan.