As for cross fit, I’d suggest passing on it. Newbies are too often motivated to the point where they try to progress too quickly. There is a ‘hardcore’ culture in cross fit gyms and nowhere else have I seen more people sacrifice good form and safety so that they can outdo the person next to them. I’m not knocking it all together, but just warning people new to it that many crossfitters get hurt a lot and don’t concentrate on perfecting proper form.
Sucking in your stomach hoping it will magically disappear? Want to fit into that gorgeous dress hanging in your closet? Desperately hoping you can pull off a swimsuit this summer? The only answer to your prayers, which you already know, is exercise. Like the wise say, there's nothing like starting today. Exercising is the best way to burn calories and build muscles, so don't make excuses. Instead, make progress. You need to take care of your body, and only you can make a difference. I'm not telling you it's going to be easy, I'm telling you it's going to be worth it. Look in the mirror, note: that's your competition. You have to do it for yourself.