This is quite straight forward. Go to your WordPress admin url (E.g: https://your.domain.name/wp-admin/) and login. You'll need to be at least an author role to be able to create pages.

You can create a page just like a normal WordPress page. Go to Pages > Add New.

Since we have the Divi builder with us, let's use it. Select the Use Divi Builder.

Before we jump straight into building our page, let's fill up our page meta-data for SEO searches. It is very important that you should always focus on 1 keyword and structure your title and short description to be concise and percise. This will help you write a meaningful content page which helps you to earn better ranking. Once done, save it.

REMEMBER:

Write for human to read! Not for robot. Eventually, traffics comes in as human interested in reading your contents.

Now select the correct language you want this page to be. Save it.

Once all are done, we'll use the Use Visual Builder editor to edit the page, "What You See is What You Get" style.

Most of the Divi Builder components are quite straight forward to use since they're drag and drop in style. In case you need a training or getting more from the Divi Builder, visit more Getting Started tutorial page for a more comprehensive trainings.

Credits to Elegant Themes for their Youtube Divi Builder interface.