Enabling portfolio topics in Harmonic Theme

I have installed wordpress in an external hosting, and I am trying to use Harmonic theme; I cannot see the “Project” tab on the left column menu in my dashboard; In the home page of Harmonic Theme it is said that I have to go to settings-> write-> custom content:

“In your site’s homepage, go to Settings → Writing → Custom Content Types and make sure the “Portfolio Projects” option is enabled. When you’re done, save your changes.
Add projects under the new Portfolio menu item in your sidebar.”

But in my dasboard there is no the “custom content” section under “settings-> writing”

When I go to a “portfolio” page, a message: “No project found; ready to publish your first porject? and a “get started here” link is displayed, but if I click on this link “Invalid post type” is displayed.

How can I get portfolio projects be supported on my instlallation?

Regards

JL