How to create One page?
The best way to start is to install demo content. If you want to install one page demo please refer to the article: Installing Demo Content. You will be able to see how all elements on the single page are set.
Please have a look at the following steps, how to achieve one page:
1. First of all, navigate to the Bold Page Builder and edit desired section. Insert in required Custom Tab Element ID attribute:

2. Then in Appearance > Menus add a new Custom Link and as a URL insert custom ID atribute with #.
For example: #about

For more info and detailed instructions please refer to our Online Theme Documentation.