How does a rocket get to space?

By being powerful enough to achieve escape velocity from the Earth. As this is 7 miles per second, it has to be a big rocket.

It is called "thrust" a downward force (by the rocket fuel) exerts on the Earth. Then as per Newton's Third Law "Every action has an equal & opposite reaction " Earth offers the Recation force that puts the rocket away from it & in an upward path towards the sky.

High pressure being released from rocket ignition. If your young think of letting go of a helium balloon, and watch how the presure being released causes it to move on its own. Also the fuel is being burned when it exits the rocket, which I believe causes more pressure. Then if it was just coming out like helium ballon.

Lots and lots of rocket fuel. Pack it into the bottom and then shoot it off. As it goes through the atmosphere, it drops the stages of fuel. Once one compartment is all used up, it detaches and falls off, then the next compartment lights up and continues to push until eventually you break out into orbit.