Ok. I think figured it out:
Here’s an explanation for begginers like me…
1. Go to “Categories” in the Dashboard
2. Click on the category you want to use
3. You will see that in the URL, after < tag_ID= > there will be a number. In my case: 29. So it looked like this:
mysite/blabla/term.php?taxonomy=category&tag_ID=29more blabla
3. Go to the shortcode and, after < cat= >, write the number you found.
For me, it looks like this:
[rpwe limit=”5″ thumb=”true” cat=”29″]
That’s it. Hope it was clear.
Regards!