The design is not bad but the header looks plain you should get a professional logo and some graphics for the header.
It's actually a very nice layout but where's the logo? Where's the eye-catching header? You want to catch people's attention with your logo. Good choice using Joomla, though!
I don't like the choice of colors. It isn't bright. Looks boring. There's also no proper header. It's better to improve it a bit...
As stated above, add a header or something to make the site look more professional. Also, get rid of "pagina de start" from the title tag. That is just adding extra characters for no gain.