If you need help on commands in bash. You can get to it quite easily.
If you don't have it already. I suggest to install man-db package first
yum install man-db
Then you can use man command to view the manual for a specific command (ls in this example):
man ls
?searched_string you can search all manual from bottom to top for "searched string"
n - next occurrence
q - quit
If you re not sure which manual page contain information you need, you can search all for specific string
man -k searched_string
You can also show manual for bash
man bash
Or you can show help page for specific command (if he has any) using --help option
ls --help
or
ls --help |more
For bash built in commands you can use help command
help
help for "specific command"
help kill