Do I need to install the Beaver Builder child theme?
Well you're not forced to use it, but here's why it's always a good idea to install a child theme.
Unlike some themes where there are various flashy child themes built on top of a framework theme, the Beaver Builder child theme that's available for download on your My Account page is blank.
Why blank, and if so, why do you need it?
So that any code customizations you make don't get overwritten by updated versions of the parent theme.
Even if you think you're not going to add any code customizations (CSS, PHP, JavaScript) to your website, it's a best practice to install the child theme anyway. You never need to update it, and if you ever do want to add some code, it's going to be a lot easier than trying to install the child theme after you already have a working website. The Beaver Builder Knowledge Base has lots of code examples that you can just copy and paste into your child theme.
See this WordPress Codex article for more information about why to use child themes. WordPress has instructions for creating a blank child theme, but we've made it easy by creating one for you to download and install.