Fusion Builder is one of the most intuitive and comprehensive page building tools available. I have tested and used many different ones and I love the simplicity and stability of this builder. The editor is created and maintained by Theme Fusion, who built the Avada theme, so the integration is flawless.
Please watch the videos below for a brief overview of how to edit the pages on your site. This assumes your site is using the Avada Theme. I can answer any further questions, but this will get you started.
You can find more information on their YouTube channel.