You can create and set a landing page to your website to introduce people to your website. You can either create a custom Welcome page or have your Portfolio open to a specific Project or Gallery.
You can create a new page by clicking (Add Content) on the left side of the screen and create a new Page.
Creating a new page acts a lot like creating a Project, so you can add images, embedded information, Creative Cloud files, and text. The only difference is that these Pages aren't found within Galleries--they exist as separate items in your navigation and content manager.
Once you've identified or created your Landing Page, click (Edit your Settings) and navigate to Landing Page. In the first drop down, you can select the page you've planned on using for your Landing Page.
Note: You may have to Publish your site before being able to set your original 'Projects' Gallery as your Landing Page.