All you need...

All you need to start working on your chest is the floor; push ups are an underrated exercise.

You don't have to do 100 a day - do one. Do two the next day. Take breaks, and make sure you breathe. 

Can't do one? Instead of placing your hands shoulder width apart and using your outstretched feet as a pivot point, use your knees. Do what you can and you'll be surprised as how quickly you progress.