Hello!
First, you can check the source of the page from the “More actions” button on the top right of your screenshot > Source.
This should bring you to a display of the code used to generate this page.
Once you have the source, you can read it and try to understand how to replicate a similar style and see what you want to keep or change on your page. Here is the documentation of the XWiki syntax used. If there’s still something you have trouble understanding by yourself, feel free to ask on this post about it