I tried just "pico" but that didn't prove fruitful either.
pico is a text editor... so really you can use whatever your favorite one (if you have one already).
It's strange that you don't have pico, either that or pico's not installed in the default location and/or the PATH doesn't point to it.
My favorite editor is vim... so the command he suggested would be like:
So the pico, vi, etc is simply the program opening the file .profile (the . means that it is a hidden file so it won't appear on an ls unless you add the -a option [ls -a], which is like saying "list all files" (try ls --help for more info or check your man pages) ).
Anyway, back on topic.... so if you have any text editor, be it emacs, vi, pico and the command "<favorite text editor here> ~/.profile" doesn't work, you could open the GUI version and use the File -> Open method to find/create your ~/.profile file
sorry if any of that went over your head; I know learning Linux can be a daunting task, but there's plenty of documentation out there and forums for guidance like this one (however I might suggest swapping to the System Administration -> Linux / Unix / BSD forum if you have more questions about Linux in general and not Python).