Thanks for writing in.
Most of the videos you will find for X will also be valid for PRO at this stage of the product.
At the moment PRO does not offer demo content, so this part you cannot count on.
On your Wordpress Top Admin Bar you will find the word PRO, hover and launch.
There you will find: Options, Content, Header, Footer
On Options (Theme Options) is where you will set the general style of your website. You can choose the stack, the general aspect of your buttons among other things. I encourage you to explore one by one.
On Header and Footer, you will find the header and footer builders. This is at this stage the biggest advantage of PRO in relation to X.
The header and footer builder allow you to build highly customizable headers and footer, I believe there is no other WP theme which offers such a flexibility.
The best way of learning is by using it of course but you can check this video before :
On Pro Theme we use the page builder, so when you create a page, click edit with PRO and you will get to the page builder. The page builder is very similar to X Theme page builder Cornerstone, so you can watch some tutorials on how to use Cornerstone, it is the very intuitive builder, but as any new tool, you will have to face a small learning curve.
If you want to change the same element throughout the site with CSS you can use classes, but sincerely, so far you have quite of a learning curve, so I would recommend you concentrating on that later. There is a great series on CSS on the youtube channel Dev Tips - CSS Basics This guy is pure fun and he gives the best tutorials I´ve seen so totally worth checking, but as I said, maybe later
Finally, Once you create your page on the page builder you have the templates functionality, so you can save your content as a block or page template and using on other parts of your website.
Good luck, X and Pro were the best themes I found on the market ( and I am giving my personal opinion, before joining theme), sometimes things were not easy at the beginning, but we from support are here to guide you and assist you, so reach us if you have any questions.
Hope it helps