2D Platformer - Sinking into colliders & bumping over tilemap

Hey fellow Unity Developers, hope you're having a nice day!

I'm currently developing a 2D Platformer and i have this issue with my player sinking into colliders and also hitting bumps when moving over an platform made up from a tileset.

So my question is, how is the best way to do a 2D Platformer Controller, and handle collisions - i'm still fairly new to Unity and C# so would love to learn about new ways to achieve this.

Here is my PlayerController:

 using System.Collections;
 using System.Collections.Generic;
 using Com.LuisPedroFonseca.ProCamera2D;
 using UnityEngine;
 
 public class PlayerController : MonoBehaviour {
 
     [Header("Player Movement")]
     public LayerMask playerMask;
     public float maxSpeed = 7f;
     public float jumpTakeOffSpeed = 7f;
     public bool canMoveInAir = true;
     public Transform groundCheck;
 
     public bool grounded;
     private float playerInput;
     private Vector2 velocity;
     private Rigidbody2D rb2d;
     private float groundCheckRadius = 0.2f;
 
 
     void OnEnable()
     {
         rb2d = GetComponent<Rigidbody2D>();
         ProCamera2D.Instance.AddCameraTarget(transform);
     }
 
     void Start () {
 
     }
 
     void FixedUpdate()
     {
 
         velocity = rb2d.velocity;
         grounded = Physics2D.OverlapCircle(groundCheck.position, groundCheckRadius, playerMask);
         Debug.DrawLine(transform.position, groundCheck.position, Color.red);
 
         Move(Input.GetAxis("Horizontal"));
 
         if (Input.GetButton("Jump"))
         {
             Jump();
         }
     }
 
     public void Move(float horizontalInput)
     {
         if (!canMoveInAir && !grounded)
             return;
 
         velocity.x = horizontalInput * maxSpeed;
         rb2d.velocity = velocity;
     }
 
     public void Jump()
     {
         if (grounded && velocity.y == 0)
         {
             rb2d.AddForce(Vector2.up * jumpTakeOffSpeed, ForceMode2D.Impulse);
         }
     }
 
     public void Die()
     {
         Destroy(gameObject);
     }
 
 }