Whenever possible, buy smart home devices that can be controlled locally (that way your home does not depend on other’s cloud servers which may be unavailable).
Start small with either WiFi/Zigbee devices. I hear a lot of good reviews with Shelly as well as Sonoff (WiFi).
However, if you plan to have a LOT of smart devices in your home, consider using Zigbee. For the coordinator, you can consider using this-