I am beginner trying to make 2d platformer but when player reaches the end camera still follows him and camera shows things out of the world.
It’s been about 3 months since I worked with Cinemachene, so this is off the top of my head. What you need to do is set up a second “passive” virtual camera that doesn’t have any behavior, and you can set its position to any location you like.
When your player reaches the end, you will set the passive camera position to the position of the follow camera then switch the view to the passive camera by lowering the follow camera’s priority. The follow camera will keep moving, but you have switched the view to the passive camera. See this discussion where Gregoryl talks about it: