It all looks strange because you seem to begin from nothing. The first casino doesn't even have more than one table. Of course I understand that all that is to introduce the tutorial. So your job here is to drag every comming customer to the type of game that they want, which is seen in the thought bubble near their heads.
After that you are to supply them with whatever they want to make them spend more money in the casino. One of the things that they may want is a drink. There is a waitress for that at the bottom of the screen. You just drag her to the customers. Or if they want to cash out you drag them to a special window.
Thing are pretty slow at the beginning, and the game seems to have nothing like chaos, that was promised in the title. It does get more challenging later though. There are many upgrades that you can buy as you earn more and more money. One of the things that really dislike in this game is that there seemed to be no tasks lining-up feature.