We've integrated the Elementor Page Builder plugin with the theme as we think it's the future for simple, drag and drop editing in WordPress.
The best thing to do in my experience is to dive right in and start playing with it - you'll be amazed at how easy it is to use.
I'd recommend adding the 'Post Duplicator' plugin if you're starting off. Once installed - it adds an option to make a duplicate of any existing page. So you could make a copy of the homepage for example and practice on that.
Tutorials
There are a number of great tutorials on Elementor online. Here are a couple of note.
Elementor Docs
Elementor's own site is a great way to start - https://docs.elementor.com/category/5-getting-started
Building your First Pages in Elementor