MyBB Community Forums

So lets say I want my forums to be like this:
Domain.com/ForumName
Domain.com/ForumName2

Things like that.

Is that an htaccess code? If so, what is it?

You will have to move all MYBB files to: Domain.com/ForumName2 then edit your settings.php file.

My bad, forums as in "General Support" and "Installation and Upgrades Support" for this site.

Not forums as in different sites.

You'd need to install the Google SEO plugin.

http://mods.mybb.com/view/google-seo

I don't understand, do you want your URL to be the same as your thread title or forum title then you need SEO plugin as @Nathan Malcolm suggested above!

Like, if my website is catforums.com, so it's catforums.com/index.php
And I have a forum for a specific breed of cats, it should be, instead of:
http://catforums.com/forum-1.html its
http://catforums.com/calico

Yeah you need to install SEO plugin!