Sadly I must agree with The Realist at the basic design part, since it is basic, but because you specified that you are new to all this, I understand.
As for the language, I expect that it is directed to Spanish language speaking people (I think it is Spanish if I am not mistaken), so there is no point to complain about that.
To edit the default page for non registered users, you must edit a few of the scripts (for text shown) and the templates via Admin Control Panel...
Besides the design, everything else is nice, congrats