2D Enemy ai

I am making a top-down 2D game and have a basic enemy movement script. It works well I just don’t know how to make the enemy walk around walls rather than walk into the wall to get to the player. I am using the free version of unity. Any and all help is appreciated.

NavMesh and unity’s navigation system are free from 5.0 onwards.

You can also do a search for the A* pathfinding project.