How to avoid jittering / stuttering when colliding with objects in 3D?

(Firstly, I want to note that I'm very new to unity and coding in general)

So, I've been making a first person controller that lets you move around with W.A.S.D and look around with the mouse. It works fine until I add objects. When my characterObject collides with an object; particularly a kinematic object, and then continues to move in the direcion of the object, it jitters and stutters into the object. In some cases I was even able to push myself through solid kinematic objects even though the object has a collider.

I'm not sure how to fix this, I just want my character to hit an object and then stop smoothly like hitting a wall in real life.

This is my code for movement:

public class CharacterController : MonoBehaviour {

 public float speed = 10f;
 private Rigidbody rb;

 // Start is called before the first frame update
 void Start()
 {
     Cursor.lockState = CursorLockMode.Locked;
     rb = GetComponent<Rigidbody>();
 }

 // Update is called once per frame
 void Update()
 {
     float translation = Input.GetAxis("Vertical") * speed;
     float straffe = Input.GetAxis("Horizontal") * speed;

     translation *= Time.deltaTime;
     straffe *= Time.deltaTime;

     transform.Translate(straffe, 0, translation);


     if (Input.GetKeyDown("escape"))
     {
         Cursor.lockState = CursorLockMode.None;

     }
 }

}

And this is my code for the camera movement (mouse movement):

public class CamMouseLook : MonoBehaviour {

 Vector2 mouseLook;
 Vector2 smoothV;


 public float sensitivity = 5f;
 public float smoothing = 2f;

 GameObject character;

 // Start is called before the first frame update
 void Start()
 {
     character = this.transform.parent.gameObject;
 }

 // Update is called once per frame
 void Update()
 {
     var md = new Vector2(Input.GetAxisRaw("Mouse X"), Input.GetAxisRaw("Mouse Y"));
     //md = Mouse Delta

     md = Vector2.Scale(md, new Vector2(sensitivity * smoothing, sensitivity * smoothing));
     //Multiplies the mouse movement with the sensitivity and smoothing variables (Applies them)

     smoothV.x = Mathf.Lerp(smoothV.x, md.x, 1f / smoothing);
     smoothV.y = Mathf.Lerp(smoothV.y, md.y, 1f / smoothing);

     //Lerp is applied to smooth the movement of turning rather than snapping it into place


     mouseLook += smoothV;
     mouseLook.y = Mathf.Clamp(mouseLook.y, -90f, 90f);

     transform.localRotation = Quaternion.AngleAxis(-mouseLook.y, Vector3.right);
     character.transform.localRotation = Quaternion.AngleAxis(mouseLook.x, character.transform.up);
 }

}

The movement script is attached to the characterObject which is just a capsule, and the camera script is attached to the camera which is a child of the characterObject, Thanks!

(I use C# + Unity)