I let my 97 Geo Metro sit too long without driving it and now I cant get it to start, its the fuel. Help!?

From what I have been told, if the gas sits too long it will cause it to not start. It started fine last week, I havent driven it as often as I should have though. It is turning over very well and all electrical is working properly. Its not fuel injected so I have no clue what to do. I have been told to use a fuel additive but dont see how thats going to work when its not starting. Fuel pump is engaging as well. Any help would be great! Thank you!