Honestly speaking, getting a six pack is probably one of those things no one Has to go to gym for. And I also think people go to gym and think that is the way for everything. Well No. Body Building and fitness are two different things.
Generally If you just want to get in shape and have a six pack, that's not really bodybuilding or gym necessary, you don't need a ****ing coach or program, you just need to Get out and Sweat, and get on the Floor and do Reps.
So here, If you have carpet floors, great, if you don't, just buy yourself a fitness mat, should only be 5 dollars in any store. Start by doing a quick warm up, just turn your hips in circles and front to back, side to side. This will prevent getting any injuries or feeling too 'pulled' post workout.
Now, if you do the regular situps, you may need some kind of weight, or a way to trap your feet under something, or you'll get unbalanced and rock. You can do this also without any weight, but it tends to not be good for the back.
In any case, I always recommend situps variations. for instance, try just crunches maybe, meaning just lift your upper body to about 45°, and on the way down, try not to always touch the floor, make it a whole set in 'tension'.
Another one, keep your legs up, and crossed, with knees at 90° and do crunches like that.
Another one: Lie completely flat on the mat, eyes looking at the ceiling, at the same time, pull your upper body up, and bring one leg towards you and touch your knee, just do it alternatively, one leg at a time.
Now, I don't know what your condition is, so if you have like a belly, doing ab exercises won't make a six pack appear. It will work your muscles, but it won't show unless you lose the weight, and the only way to lose weight is running, cycling, rope skipping, any cardio exercise. If you combine both things, then you'll do Well.
Best Wishes and God Bless.
