The Zotero Library has 3 sections as shown below. The toolbar, across the top of the pane allows you to perform functions including creating collections and groups, importing references, creating items from web pages and locating items. Learn to use Collections to organize your library in the box below this one.
You can sort the references/items in the center column by title or author by clicking on headers at the top of the column. Choose the fields displayed by clicking the sort icon (), found to the right of the column headers. Checking properties in the dropdown menu adds them to the center column, and unchecking removes them. Learn more here.