I promise I won't tamper with them and break anything.
Well, I dunno. . . . Oh, all right.
The apps in the Applications folder are disguised folders full of application files, as yogi says, so if you decide to uninstall one, most of the program goes into the trash in one fell swoop.
Where are the preference files and other stuff in the library?
There are three (count 'em, 3) libraries, which probably will add to any confusion.
The library that probably most affects you is the one in your home folder, inside the users folder.
The hard drive or partition also has its own library. Click on the hard-drive icon to open it, and you'll see that library folder.
The System folder also has it's own library. But everything inside that library is write protected, so you can ignore it.
A Macintosh convention in writing file pathways is to use the tilde (~) symbol to signify the user's library, not the hard-drive library. If the ~ is not there, the pathway refers to the hard-drive library.
So, ~/library/preferences
means the preferences folder inside your home-folder library.
/library/preferences
means the preferences folder inside the hard-drive library folder.
Inside the preferences folder are plist files, or preference list files. These are text files and can be opened and read with TextEdit. If an application repeatedly crashes or repeatedly does something else it shouldn't, chances are the app's plist file is corrupt. It's safe to trash plist files; the app will write a new one the next time it starts, but you'd have to change the app from its default settings again.
These plist files are among the few small files that aren't deleted when you trash an app.