Home Assistant - Why the necessity for fiddling with configuration files?

As a newbie to HASS, it is somewhat bewildering to configure.

I bought a collection to IKEA Tradfri devices to start my HA fun. The IKEA gateway seems to be somewhat unreliable, so I decided to buy a CC2531 dongle, and install Home Assistant. Flashing the dongle was not too hard, and installing HASS OS on a Raspberry Pi 4 was a breeze. I factory reset (4-clicks) an IKEA dimmer switch, and the CC2531 recognized it, and the device appeared in HASS. Similarly, I reset a Tradfri lamp, and it also appeared in HASS. So, I have two devices, and I want to create the “Hello World” of home automation, using a wireless switch to control a wireless lamp.

In the IKEA setup, you pair the switch to the lamp, and they are then linked together in a “room”. All devices in the room respond to the one control. Further lamps paired to the same switch are added to the same room.

What is the equivalent process in Home Assistant for pairing controls and lamps together? Do you always need to edit configuration files, or can this be done through the UI? If through the config file, how do you do this?

Sorry about the noob question, but it’s not clear from reading the docs.

Regards,

Paul