How do you see the process through the proc file system?
How do you see the process through the proc file system knowing the id process?
Almost half the answer you wrote on the question.
Yeah, you can see the contents of the various files on the catalogue.
The meaning of the files/catalogons and their contents is explained, for example, http://man7.org/linux/man-pages/man5/proc.5.html or in the documentation for the programme linux: https://www.kernel.org/doc/Documentation/filesystems/proc.txt