Understanding the Admin Panel
The items in the black menu on the left are your controls for the site. You have access to website Stats produced by a program called JetPack. From this panel you can also start creating blog posts with the Posts option or pages with the Pages option. The Media option allows you to upload new images, documents, videos or audio files (remember you only have 3GB), or edit or delete existing items.
You can control the appearance of the site with the Appearance option. Here you can customize your existing theme, or even add a new theme (there are many free options available). Widgets, which are blocks of content that can be added to certain parts of your site depending on your theme's settings, can be set here as well. You can also add and edit menus.
Users and Settings are other options within the Admin panel that may be useful to you as you setup and configure your site.