Your existing Behance projects will automatically be imported to your Portfolio site. You can find them in your Default Gallery or in Manage Content.
If you'd only like select Behance Projects to appear on your Portfolio, select Manage Content from the Toolbar. You can then use the toggle buttons to hide the Projects that you do not wish to display on your Portfolio.
You can also delete the Projects from your Portfolio site entirely by clicking Manage Content > gear icon > Delete Project.
** Please note, deleting a Project in Portfolio will not remove it from your Behance site. You can always re-import your Behance project by unpublishing and republishing your Behance Project.