I have my portfolio done but i want now that all the portfolio has the entire width of the page like the demo.

And by other way, in the demo, above the portfolio it have a filter
" See all / Landscapes / Nature / Science "

¿How i can do it all this?

If it’s easier , I’d like to install the demo , I’ve tried but I can not.

You just need to go to Edit Row and set that row to Full Width Stretched.
For the filter you need to include the slugs for the categories you want to show in the include="" part, just like it’s shown on the documentation page.

The FULL WIDTH is not working.

It’s working fine. You didn’t set it. I’ve set it for you now.