I would like to know how can I change the title of my page to be just "FinanzasYa" instead of "Category ArchiveFinanzasYa"
The best way to modify how a theme presents an archive is to create a child theme and then create a specific altered version of the page you want "fixed".
Template files follow a hierarchy with the most specific file available used.
In your case, you could create a file called something like
category-finanzasya.php (depending on the slug the category has - I've picked what it would probably default to). Copy the contents of category.php from your parent theme (that's the one you are making a child version of) and then edit it as much as you like.
For everything else, WordPress will use the original theme but, just for that one category archive, it will use your custom version.