If I understand what you're trying to say, you'll need to move your /forum/ directory up one level so that it's in the root directory (and set up 301 redirects accordingly). Otherwise it's best to just make your own file with the HTML contents and use it as your homepage.
With XF2 it's really simple to add a Page as the homepage and populate it with widgets to create a "portal" page. As a few people have asked how to do it I thought I'd post this quick guide. Go to admin.php?nodes/ and click Add a Node Select...
I just installed this addon.
My homepage at the moment is xenforo brand logo.
I am not good at html code. Can someone share me a simple html code that can look different from default xenforo homepage?
Thank you guys