Check your time on Nursing Mothers, once they only have a few minutes left.  Be sure to change their job to something other than parenting.  By leaving them in Parenting, they will continue to have babies and this can cause big problems with your food supplies and ability to get jobs completed.
 
This can also be a problem when you leave someone Farming, when you're food sources are limited.

You have 2 types of advertising that you can do. 
 
1:  Use the megaphone at the bottom of the game screen and you can advertise there.  Just be careful not to use all of your money too quickly.  You can always go back and adjust your advertising later.
 
2: After you have built any of the rides, shows or games you just click on whatever you want to advertise.  It will then give you a small block with all the info about that item.  At the very bottom of that block you can mark that you want to advertise that item and how much you want to spend.  Just be sure to watch your money, you can always go back an adjust the dollars again later.