How do I select a part of a vector Ex: rectangle.
Hello everyone,
I use Animate CC, and I wanted to switch to the illutrator however, for me to completely change I wanted to know: How do I select only part of a vector?

Example: See the images that I attached, in the 1st image I select only a part of the rectangle with the "Selection" tool and with that I can (Change the color of the selected part, delete and Move (2nd attachment), etc.) .

I have tried several ways to do the same thing only in the illutrator, however without any results.
I would have some way to do this WITHOUT USING PATHFINDER, because if I use the pathfinder I will have to create a new vector (another small rectangle, and do the process of removal, or joining, etc.).
Is there a tool inside the illutrator in which I can select only part of my vector?
I will be waiting for help.