How do i move a cube like an actual cube?,How Can i Move a Cube?

Like mentioned in the question, how do i do just that?

 void FixedUpdate () {    
     if (Input.GetKey("w"))
     {
         rb.AddForce(0, 0, w*Time.deltaTime,ForceMode.VelocityChange);
     }    
     if (Input.GetKey("s"))
     {
         rb.AddForce(0, 0, -w * Time.deltaTime, ForceMode.VelocityChange);
     }
     if (Input.GetKey("a"))
     {
         rb.AddForce(-a * Time.deltaTime, 0, 0, ForceMode.VelocityChange);
     }
     if (Input.GetKey("d"))
     {
         rb.AddForce(a * Time.deltaTime, 0, 0, ForceMode.VelocityChange);
     }
     if (Input.GetKey("space"))
     {
         rb.AddForce(0, jump * Time.deltaTime, 0, ForceMode.VelocityChange);
     }
 }

When i run this, there is the issue when i simultaneously press W and A, the cube would slide diaganoly. Plus, The cube wouldn't move like a normal cube would, there are times when it bounces. Finally, how do i made the cube jump properly? Thanks,How can i move a cube, like an actual Cube?

 void FixedUpdate () {
     
     
     if (Input.GetKey("w"))
     {
         rb.AddForce(0, 0, w*Time.deltaTime, ForceMode.VelocityChange);
     }
     if (Input.GetKey("s"))
     {
         rb.AddForce(0, 0, -w * Time.deltaTime, ForceMode.VelocityChange);
     }
     if (Input.GetKey("a"))
     {
         rb.AddForce(-a * Time.deltaTime, 0, 0, ForceMode.VelocityChange);
     }
     if (Input.GetKey("d"))
     {
         rb.AddForce(a * Time.deltaTime, 0, 0, ForceMode.VelocityChange);
     }
     if (Input.GetKey("space"))
     {
         rb.AddForce(0, jump * Time.deltaTime, 0, ForceMode.VelocityChange);
     }
 }    

What's wrong with this code? When I try and run it, if i press W and A at the same time, the cube would be like sliding diagonally. Plus, there is the problem with the cube not rolling like a normal cube would do. Finally, how do i make the cube jump properly? Thanks