Hello, I am completely new to the topic and will be testing Home Assistant with a Home Assistant Green for the first time tomorrow. Now my question (probably extremely “ridiculous” for the community 
). Currently, I have my lamps/outlets automated through Alexa and Zigbee, and a few still through Wi-Fi. When I start HA tomorrow, the Wi-Fi lighting/outlets will be found. What about the Zigbee lighting/outlets? Can I continue to run them through Alexa for now, or do I have to integrate them into HA to continue controlling them through Alexa? If I want to control them through HA, my Home Assistant Green will need a Zigbee dongle; are there any recommendations? Or have I fundamentally misunderstood something? Thank you in advance. Regards.
Hi Andre & welcome to the HA community.
Moving everything into HA is the best idea for central control of your devices. You’ll still be able to control them through Alexa though.
So for this you’ll certainly need to turn your HA box into a Zigbee coordinator & while there are so many options I recommend the official HA device, the Connect ZBT-1.
If you have a PoE network switch then using a serial over Ethernet coordinator has a lot of advantages. You can place it central to your zigbee network for best coverage and keep it away from noisy PCs and shielding metal.
I’ve had no issues with Tubes coordinators and he offers excellent support: https://tubeszb.com/