where is the movie clip node on blender 2.83? I'm on blender 2.83 and I would like to apply a shader nodes scheme to a movie clip,instead to the single frames,but it seems that it isn't where it should be. At least,according with the tutorial that I'm following,this one :
https://www.youtube.com/watch?v=_pPGR3d9WWc
Below you can see clearly that I don't have that node anymore.
You are in the wrong node editor at the moment. The Movie Clip node is a compositing node, and is found in in the compositor.
Refer to the image below:

Currently, you are in the shader editor. So, just switch editors and you will find the node you are looking for.