If you would like to list directories first and than the files with the linux ls command you would have to execute the following ls command
ls -l –group-directories-first

The –group-directories-first  takes care of showing the directories first and than the files.

My favorite ls  alias is (add / change it in your .bashrc ):

ls -AlF --group-directories-first --color=auto
# -A => do not show the implied . and .. directories
# -l => use a long listing
# -F => appends an indicator to entries (a / for a directory)