This is where the RTFM mindset is important. If you encounter an issue, there’s multiple decades’ worth of information on the internet that will most likely immediately provide an answer.

The location of installed files is determined by long-standing conventions that were in effect even before Linux was released… but I won’t go into it. You can read about it yourself: en.wikipedia.org/wiki/Unix_filesystem

This is my point: do you need to know this? Nine out of ten cases, this is not useful knowledge. I’m a sysadmin and even I don’t need to know where each program’s files are located. You should not be interacting with these files at all. Let a package manager do that.