Start with one useful thing
Rather than automating everything at once, most people are happier starting with one clear win, smart lighting, a video doorbell, or a couple of smart plugs, and building from there.
Pick one ecosystem to begin with
Devices that speak the same smart home standard talk to each other far more reliably. Deciding this early saves rebuying devices later.
Let it grow with you
Once the basics work reliably, adding cameras, sensors or voice control is a much smaller step than starting with all of it at once.