Your e-portfolio should have a name like "Arthur's E-Portfolio for Design Tech." Create this within New Google Sites. Hit Publish.
Now hit the share button (it's a person with a + symbol). Change the publishing settings to "anyone can find and view." This allows you to share your e-portfolio with someone outside of ISM (like perhaps a new school or summer program).
Now hit the drop down arrow on "publish" button. Click "view published site." Copy this url to the published e-portfolio and place it here, next to your name.