When I'm driving on a hot day my brake pedal get really hard then the car starts To shake. And my car starts to smell like burnt rubber? What's wrong please help
I would assume this means you have lost your intake manifold vacuum due to a vacuum leak. The brake pedal gets hard because you have to provide all force yourself without any braking assistance from the vacuum powered servo.
Also, the car shaking probably comes from the engine, which now has more air than it needs to have.
See here how to find vacuum leaks: Finding a possible vacuum leak