You can find the link of your portfolio by clicking the little pencil button when you hover the White Label Dashboard menu item. Then Click on Web Design Portfolio to customize the menu item, then click on it.
It will open your portfolio :
You can then link to it from your website.
Wordpress Plugin Activation
In your SEOReseller Wordpress Plugin, you'll find a section to activate the portfolio feature and choose its url. Once activated, you will have a new page where you can see your porfolio embedded.