Here are a few things you can try:
Push-ups, of course. You can do them anywhere, anytime. They're good for your entire upper body. . . chest, arms, back. You can eventually work up to where you're doing a few hundred a day. (It's not as much as it sounds.) It will make a difference.
There's also a little device called the Perfect Push-up, which you may have seen advertised on TV. They are probably even better than regular push-ups. They've started selling them in stores for about $30. I know you mentioned you're a little short on cash these days, but thought I'd mention it anyway.
Pull-ups / chin-ups (using underhand and overhand grip) are great for biceps, back, shoulders, getting a V shape. . . are you near a public park that might have them? Some do. (Just don't buy the chin-up bars that you hang in the doorway. Those have a tendency to fall and you could really injure yourself.)
Some parks also have fitness areas where you can do elevated push-ups, etc. And those are free.
Running and jump rope. Great for cardio and both will help you get cut. You probably already have a pair of tennis / running shoes. If not, some running stores actually have a program where they'll give you a pair of donated old running shoes, which is better than not having them at all. First Coast Sports, which is in FL, just announced this on their Facebook page.
As for a jump rope, that costs only a few dollars.
Sit-ups don't require any equipment and you can do those at home.
Also watch your diet. . . replace junk food with fruits and veg. It's a drag at first, but eventually you'll like the change. It's cheaper too.
Also: Some YMCA's have a program where your payments are based on your income. If you're not making a lot these days, or if you're unemployed, you can work out an incredibly cheap deal with them. Like next to nothing.
I can't say that every Y does this, but it is a big part of their mission to keep people healthy regardless of income status. I urge you to check them out.