Button in product listing

how can i create a button in product_listing "+ info" that goes to the product page? dont know how to use php

You don't need to know PHP for that. Edit the file "listing_img_title" of the view "product" via the menu Display->Views and add some HTML like that:
<input type="button" onclick="window.location='<?php echo $link; ?>';" class="button" value="+info"/>

Thank You! another small question i put alt="añadir cesta" but it doesn´t display.How can i do it?

alt is for images. You should try with title instead.

More information on input HTML element attributes here:
www.w3schools.com/tags/tag_input.asp