Organizing by first name
The ability to organize your contacts by first name is on your default contacts table. Simply click the "Name" column to sort your contacts alphabetically, and click it again to sort them reverse alphabetically.
Organizing by last name
To organize your contacts by last name, you must first create a last name column on your contacts table. Click the green "Columns" button.
A window will appear, here is where you can find all the columns you can customize your contacts table with. On the left list select "Last Name" and then select "Update Table".
Now on your contacts table you can select the "Last Name" column to organize your contacts!