So I did, very sorry. Thanks for your reply!
P.S. For anyone who can’t be bothered reading all that, simply insert:
<?php foreach((get_the_category()) as $cat) { echo $cat->cat_name . ' '; } ?>
…anywhere in The Loop to display the category of the current post.
I needed the Category ID only, in text form [non-link]. So, if that is what you are also looking for, here is the code I found and tested: [it works].
<?php foreach((get_the_category()) as $cat) { echo $cat->cat_ID . ' '; } ?>
It displays only the cat id (number) instead of the name.