How to change command line prompt?

[joe at actionline.com]

I recently purchased a new Dell laptop, delete M$,
installed Linux Mint, and I'm in the process of
setting it up the way I want it.

How can I change the command line prompt from the current:

"joe at joe-dell-Inspiron-3542:>"

to just: "joe:>"

Also, I'd like to be able to turn the touchpad off and on
but the only suggested method I have found to do this
does not work for me:  synclient TouchpadOff=1