To answer no. I am sure most cocktail waitresses know how to mix drinks if they have done it for so long, but being a bartender and a server are two very different things.
If you do not know anything about drinks, you will first need to either find some books or attend a class. Once you learn how to mix drinks, what goes in what etc, you will then need to hit up some bars and see who is hiring.
If you are in a larger city you most definitely will need to know somebody on the inside, or like in Vegas you will need what they call juice. Remember its not what you know, its who you know (but you must know how to mix drinks). Confusing I know.
Being a cocktail waitress, especially if you are an attractive woman is a far easier job to get in most places.