I've gone mad – could someone please help (posts problem)

Ok, I’m designing a basic site and am mostly learning coding as I go along. I read up on how to remove the dates from posts in a category, but now am trying to repeat the process but can’t for the life of me remember how I did it!
The category ID I did it for is no.6, and I have a php file in my child theme called category-6. I was certain that’s how I did it, but there doesn’t seem to be anything in it to remove the date, if I copy it and change the ID it doesn’t work for the other category, and even if I delete the file the dates still don’t show on number 6!
This is driving me insane, I know this is a stupid question but please could someone help me. If you need to see anything else just let me know.

Here’s the page I have removed dates from

http://1070009035.test.prositehosting.co.uk/other-crap/

Thank you