You can build a completely new template from scratch. Just head head to 'Build template' in the left-hand side bar.
To create a brand new template just click on ‘Build template’ in the left-hand sidebar of your dashboard. Give your template a name (you can rename it later).
Your template will already have a section and a line in it so you have somewhere to start from.
Check out the following articles for help building your new template:
Add blocks / Add or change lines / Edit any text / Reorder content / Change buttons / Create or edit links / Undo, redo or preview / Revert changes / Copy from a template