How to create a ground/terrain/floor that won't respond to gravity or objects falling on it?

Hello! I researched for hours before asking this question. I can't seem to find a good answer or tutorial that addresses my issue.

So, I want to create a ground or terrain that the player can walk and jump on, much like in Mario or any 2D game with gravity. The game is 2D and has two game objects: a player and the ground. Both game objects are outlined below:

Player Rigidbody 2D, gravity scale = 1 Box Collider 2D

Ground Rigidbody 2D, gravity scale = 0 Polygon Collider 2D

The problem is that Player crashes into Ground and pushes Ground downward infinitely. How can I make a terrain or ground object that stays in place and acts like a surface that can be walked on?

Thank you for your help!

tundoo