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