Edit .bashrc in your home directory
-or-
edit /etc/bashrc if you wish to add a global alias (you must be root).

Enter the following aliases:

alias nano='nano -w'
alias la='ls -a —color'

Note that you can use the semicolon (;) to have an alias run multiple commands:

alias cls='clear; ls'

Either login again
-or-
enter . .bashrc in your home directory
-or-
enter source .bashrc in your home directory
-or-
enter . bashrc if you're root & in /etc
-or-
enter source bashrc if you're root & in /etc