Anthony W. you need a plan! And you need to make it your mission to adhere to it.
Calorie deficit is your means. Plus exercise.
Doing loads of situps will not make your gut smaller - spot fat reduction does not work. What you need is cardiovascular exercise (and some weight lifting maybe) to reduce overall body fat, and a carefully planned
healthy diet.
Doing loads of situps as part of an exercise regime is good however
Simplest workouts are pressups/pullups/chinups/crunches/cardio - none of which require you to spend money on expensive kit.
There's lots of get fit & loose fat fast gimmicks out there, so don't be fooled into parting with your cash for something that's almost certainly too good to be true.
I like
http://scoobysworkshop.com/index.htm as far as honest advice goes, there's lots of practical information for getting fit, loosing fat or being a serious curl monkey. Have a read and see what might be in line with your goals, but make sure your goals are realistic and long term.