How to make my floor solid,how to make my floor solid

Ive been trying to make my floor solid but it won’t work and i don’t know whaat to do please help me.,Ive been trying for many now to make my floor solid but I don’t know how to please help me.

Both the floor and the objects you want it to collide with (e.g. the player) need to have a collider component (if you have a 2d game you need 2d collider components). Make sure “IsTrigger” isn’t enabled and that the two layers the gameObjects are on can collide. You can check this in Edit/Project Settings/Physics or Edit/Project Settings/Physics 2D.
Also, the objects you want it to collide with need a Rigidbody or Rigidbody 2D component.
Here is the introduction to colliders: Unity - Manual: Introduction to collision

Another problem you might have is that the floor has a collider but your player might not have a rigidbody
set the rigidbody collision to Continuous and add a capsule collider if possible