Noob mistakes with your car

I used to have 1980 CJ-5. Great little toy. Gas leaked like crazy out of the original tank so I put in a new one. All was well when I put about 5 gallons of gas in it afterwards. Fast forward about 2 months. I only would get it out every now and then to cruise around in. I go to start it up... Nothing. Spun and spun all day long but never cranked. Put gas in the carb and it fired right up. I deemed it to be a bad fuel pump so I traded it off for my Dart. Turns out it was just out of gas...