Question.

So I joined yesterday, and I was looking through front page, look at the bottom. it had theme selections.
I clicked on a few, then I click on "MyBB" it's for mobile, I'm on computer and I don't know how to switch back to the normal
view, anybody know how to change it back to normal forum view? Thanks.

I think at the bottom, underneath the themes, it says "go to full version". Click that.

go to user cp and options then change it in there

http://runegear.net/usercp.php?action=options

That should take you right to the Edit Options which the theme selection is in.