How do I do proper exercises?

When I started to do exercises, I will mainly do a certain count per exercise and wait a couple of weeks or so and then increased it. I did over 60 push-ups, over 50 jumping jacks, bend and touch my legs too fast, exercise too fast, and other exercise routines everyday for over a certain amount of improper hours. Then, I started to get tired, depressing, my legs are moving improperly, my spinal cord and back hurts, my neck hurts, my stomach feels queasy. I done these exercises and schedule them in a unsafe process unrealizes why this happen to me. Thanks, everyone.