How to execute python script by terminal?
If you want to list all files/folders in a directory, you should type ls not Is. It is L, not i.

To learn python, you won't need to reach ~/.bash_profile unless you need to change versions. Just use which python or  python --version and use the syntax for the version that appears. Or use online compilers for quick testing.

Suppose you have your file learn.py at Desktop, you type cd ~/Desktop, type ls to confirm, and then to run the file as a script, type python learn.py. To enter python console, type python and use it. 

Wherever your file is, you could type cd in Terminal, then drag your file into Terminal window and press Enter. Terminal will resolve the path for you.

For further help, refer to Stack Overflow.  :) 

If you want to see bash profile, open Finder, type command + shift + . to reveal hidden files and then command + shift + G and type ~/.bash_profile in "Go To". But don't edit it unless required.