Besides /bin and /sbin/, which are the other directories in Linux where executable files are stored? I am aware the whereis command is used to find location of the files, but I can't find any other directory besides these two.
Some executables files are stored in
/usr/sbin). This is usually installed scripts and apps. You should store your own scripts in
/usr/local/bin if you want to execute them from the whole system (or
/usr/local/sbin). See https://en.wikipedia.org/wiki/Filesystem_Hierarchy_Standard