Resize Camera in Blender 2.8

Hi everyone !

I have been working with Blender for a long time, but when Blender 2.8 appeared, I encountered a lot of problems, especially because I couldn’t find the location of certain tools.

This is the case now, I can’t figure out how to resize the camera in this version.
I managed to do this:

But I wish I could have only the center of the image, without having to cut the image myself after I saved the image

Do you have any idea or response at my question ?

I thank you in advance

I want to have this :