Bar Equipments

What exercises I can do with no equipment, bowling, or weight without the bar?
I want to build muscle, but I just not have the $ 100 or more to invest in a treadmill, and I'm too busy / lazy to go to the gym. In addition, I am not looking to lose weight, as I am now as underweight.
Push ups, sit ups, running, weights and put on the feet to hold them down and then do squats while holding a bowling ball about 2-4 inches from your stomach …….
Push up bars exercises EQUIPMENT EXERCISE HOME at home equipments training