moving character after jump using rigibody

Questions & Answers
1

My character have an rigibody and
able to move around and jump
both work perfectly separately but when my character is jump to the air and move,
the character can walk on the sky without falling
I believe there are some problem on my
moveCharacterAndSetAnimation’s movement vector
but I cannot figure what should I change

void FixedUpdate () {
		myPlayer.updateCharacterMovement ();
		checkJump ();

	}

void checkJump(){
		if(Input.GetKey(KeyCode.Space)&&isGrounded){
			jumpCharacter();
		}
	}

	void jumpCharacter(){
		myPlayer.rb.AddForce(myPlayer.playerGameObject.transform.up * 1000, ForceMode.Acceleration);
		isGrounded = false;
	}

public void updateCharacterMovement(){
		float horizontal = Input.GetAxis ("Horizontal");
		float vertical = Input.GetAxis ("Vertical");
		if (isMoving (horizontal, vertical)) {
			moveCharacterAndSetAnimation (horizontal, vertical);
		} else {
			idleCharacterAndSetAnimation();
		}
	}

	void moveCharacterAndSetAnimation(float horizontal, float vertical){

		Vector3 movement = new Vector3 (horizontal, 0f, vertical);
		setAnimation (animationId.running);
		playerGameObject.transform.forward = Vector3.Normalize (movement);
		rb.velocity = movement * speed;

	}
2

void checkJump(){
if(Input.GetKeyDown(KeyCode.Space)&&isGrounded){ //Instead of GetKey
jumpCharacter();
}
}

Why are you using GetKey instead of GetKeyDown. If using GetKey, it can cause several bugs and bad behaviour.
Also, since you said character should not while jumping (ie in air), use isGrounded boolean.

public void updateCharacterMovement(){
    if(isGrounded){
         float horizontal = Input.GetAxis ("Horizontal");
         float vertical = Input.GetAxis ("Vertical");
         if (isMoving (horizontal, vertical)) {
             moveCharacterAndSetAnimation (horizontal, vertical);
         } else {
             idleCharacterAndSetAnimation();
         }
     }
}