Noob here; portal page?

[MahdyE23]

First of all, I really want to thank all you guys for helping me whenever I need it.

Now, on to my noob question. How do I make a portal page? (I know how to add it to the navbar, ETC, but I mean this...)

I want the "index.php/activity.php" page to look like this:

http://prntscr.com/1fo3o2

So, the first thing they see when they join the forums are the most recent threads and everything else on the site how that forum has it. Is this like a plugin where you manually edit things, or what? I really want this figured out. This is what my index.php page looks like:

http://prntscr.com/1fto1x

As you can see, it is very different from what I want it. So, how will I make it just like this?:

http://prntscr.com/1fto8c

or

http://prntscr.com/1ftoei

I tried going to "portal.php" at the end of my forums, and I just got this:
http://prntscr.com/1ftoor

I am assuming this means there is no file; "portal.php" located in my forums directory.