In most cases, you first need to get either transform variable or rigidbody variable of an object.

• Transform.position
  *”transform” is a variable that refers to the transform of the object the script is attached to. No need to declare.
  ex) transform.position += new Vector3(1, 1, 1) * Time.deltaTime;
• Transform.translate
  ex) transform.translate(new Vector3(1, 1, 1) * Time.deltaTime);
• Rigidbody.velocity
  ex) public Rigidbody rb;
  rb.velocity = new Vector3(1, 1, 1);
• Rigidbody.AddForce
  ex) public Rigidbody rb;
  rb.AddForce(new Vector3(1, 1, 1));
• Vector3.MoveTowards
  ex) transform.position = Vector3.MoveTowards(transform.position, target.position, 2.0f);

In 2d development,

    Vector3 -> Vector2, Rigidbody -> Ridigbody2D