How to edit templates?

Hello
I want to modify the template so that the list and the detail of the events are seen in a more friendly way.
I wanted to know what are the files that I should modify and if there is any tutorial about it.
Thank you! :animar:

Hi

You can find the css files in control panel of JEM (menu item " CSS manager").
I think that there is no "template" but multiple files... (but I'm not developer!).
Maybe can help

Leo

Without any informations about your version etc. Only you are able to give the answer to you questions.

Ok. The version of joomla 3.9 and jem 2.2

Ok, welcome on this forum where users try to help other users. You don't usr JEM responsive. So it's the answer from Leo. Please consult the help too before big changing things.

Ah, OK.
I didn't know that "JEM responsive" existed. What is the difference?
Where does that version come down?
Thanks