Hi Calle,
You can install VirtualBox or VMware on your regular computer windows system, then download & import the ready to run HA image, and start fiddling right away.
Install MQTT Hub + MQTT Client on Homey, and MQTT Broker on HA.
Optional, install Home Assistant app on Homey, when you want to interact with HA devices from Homey.
When things are connected, HA starts to build a dash by itself with all devices (and will continue doing that with new devices).
Then there is Dwain’s dashboard, which is also full automatic, but editable.
Here’s a starter guide: [TUTORIAL][PRO] Home Assistant integreren met Homey