When you create an account, a notebook is automatically created for you. You can customize this notebook using the page and folder structure.
To create a new notebook, click the + on the list of notebooks on the left-hand side. This will bring up the Create New Notebook window. Name your new notebook, select a folder layout, and click "Create Notebook" to add this new notebook to your account.
More information on setting up your Electronic Lab Notebooks in Lab Archives can be found here.