How do I download ROMs?

I know I will most certainly sound dumb (I am) but I’m new to Citra (and emulators in general) and would appreciate some help. I was browsing the ROMs section of the Citra website and stumbled across a game I have really been wanting to try lately: Animal Crossing Happy Home Designer.
I saw that it had a perfect rating, which means it works flawlessly on Citra. So natrually, I clicked on it, in hopes of finding a ROM, but I looked everywhere and could not find the link! Do I need to download a ROM from the internet? Do I need an actual copy of the game I want to play? What am I supposed to do?

In order for us to provide better support, we need to see the log generated by Citra. This guide will walk you through how you can obtain the log file: How to Upload the Log File.

There’s a reason that there is a nice big banner at the top of the forum page at all times telling you to:

Clicking on the most common questions will take you to our FAQ page which under the Running games in Citra section, tells you what you need to play games in citra and links to guides on how to do it.

Please also note the second part of that banner which gives you the link to our community rules. Please read those before posting again.