Welcome, doing the same myself. I wasn’t much of a contributor prior to the great migration and I’m trying to step up my contributions in order to help grow things.
Personally my entry into Home Assistant and Smarthome was to fix a very strange series of light switches in my house that all turned on or off different lights in 1 area and I used a series of smart switches, smart bulbs and lighting groups to make them all controlled as if they were on circuit, as the cost to do so electrically was prohibitive.
Now my automations are mostly to check on the state of the house and report problems. Such as if the door to the laundry room is left closed too long (as the litterbox is in there) and to check on the state of battery powered devices to see if batteries need replaced.
I try to keep the automations simple and unobtrusive.
As far as “just works” get something that is directly integrated with home assistant and IMO if home assistant has direct access to the radio or method of communication, the better. As others have said both Zigbee and ZWave devices can interact directly with HA using a dongle and I do so with a VM on Proxmox and it works great, I do however think the ZWave JS and ZWave JS UI integrations are far and ahead of Zigbee ZHA integration (I won’t speak on Zigbee2MQTT as I don’t use it)
Wi-Fi devices are nifty but their reliance on the strength of your WiFI, internet connectivity, DHCP working, IPv6 support make them more variable than the ZWave and Zigbee standards that really just require you build a good mesh by having devices every so often that each other can “relay” through.