Sly, I can't speak to the smart bulbs because I don't use them. What I have are Homekit sockets (wall warts) that plug into the regular socket and are controlled via the iPhone/iPad Home app. I used to use the X10 protocol, where the signals use the wiring in your home to control devices at the sockets, but I moved to wireless a few years ago as I saw more and more vendors move to wireless.
Here are some things to consider that I have discovered in this process that maybe you won't hear from anybody else:
1. You need a good WiFi signal everywhere you want to put a device. I ended up getting an Eero system from Amazon to create a mesh network to cover my entire house. Not all mesh network providers work well with Homekit, so whatever you decide to use, make sure your router and any hotspots/repeaters are compatible.
2. Some units require a specific "bridge" or "hub" to control the actual devices. I have a dual-door garage, so I needed two garage door opener systems, for example. What I ended up with is from a company named Meross, and consists of a single bridge and three slaves (I have a spare). The bridge receives the signal and relays it to the two actual controllers that then activate the door openers to whatever is commanded. The bridge is wired to the controllers. Some brands of smart bulbs work the same way, so you need the bulb AND the bridge. In those cases I think the bridge connects wirelessly to the bulb, but I'm not sure because I don't have smart bulbs.
3. There are varieties of protocols for home automation. Homekit from Apple is one, Alexa has another, Ring, Google Assistant, all unique in some way. There is a movement to come up with a standard, and I think a lot of companies have signed onto a standard called "Thread," where each device becomes a relay to other Thread-compatible devices. The idea is to avoid dead spots in your WiFi cover by peer-to-peer Thread communications. I don't have Thread devices (yet) but will probably start a migration as I have to replace what I have now. There is another proposed standard called "Matter" that does the same thing. I am waiting to see who wins.
4. Some devices have their own controlling software. Most of them, if they say they are Homekit-compatible, allow you to use both Homekit and their own software. I have, for example an app from Wemo, eufy, and Leviton for those devices I have from them. But I use Homekit for all.
5. It's addictive. I started with a handful of X-10 wired switches and a push button pad so that my wife would not have to wander all over the house in the Christmas season turning off all the lights and electric candles in the windows. From bedside, she could just press buttons on the pad and turn them all off. That was 16 years ago, with about 6 units. Now, I have about 30 devices controlling indoor and outdoor lighting, cameras, doors. No locks yet, and no sensors for water leaks, or thermostats. Mostly lights and doors. I do have two in-wall switch setups. One controls my porch lights and another pair are at the top and bottom of the steps near my front door to control the lights in the entry foyer. They are both Homekit-compatible and can be manually operated as well.
6. It's both amazing and annoying. I have situation where devices drop out of Homekit even though they are in my network and I can "see" them through the eero app that they are connected and have a strong signal. To get them back, I unplug them for 10 seconds and then plug them back in to be rediscovered by Homekit. Apple has been unable to find a reason or offer any fix for it. I "lose" a device about once a week, which sounds terrible, but then I have 30 of them, so maybe it's not so bad? I'm used to it now. The amazing part is that it works, amazingly at times. I've had times when we have had visitors and the automation kicks in to set a scheduled scene. They are usually frozen as all of a sudded light just appear!
What I have are mostly wall warts that turn on/off, with a few that are dimmable. I leave the lamps plugged in and turned on, then use the iDevice to turn them on and off. Homekit also has "scenes" where a group of controllers can be defined and toggled with one press on the iPHone, or through Siri ("Hey Siri, turn on the kitchen corner light"). My automations turn on a light over my mantle to light a painting there, then at a few minutes before sunset turns on the internal house lighting I want, plus lights on my sidewalk and on a patio in the back. Then at sunset, automation turns on a spotlight on my flagpole to light the flag as required by law. At 11:30 pm, automaton sets a scene where one nightlight is turned on, the mantle is reduced to 30% as a nightlight and all but the flag are turned OFF. Another automation runs at sunrise to turn off the flag light and nightlight and to raise the mantle light back to 100%. When we travel, I have scenes for lighting to change during the evening to make it appear that someone is home as various lights go on and off over the house. The neat thing is that all of these are controllable over the internet, so I can make changes from anywhere in the world. One time my daughter needed to get in while we were in England, so I opened the garage door for her, turned on the interior lights and then talked to her through a security camera to tell here what she needed to do. When she left, I turned the lights off and closed the garage door again. Magic.
From a home automation perspective, I'm a rookie. There are controls for blinds, shades, alarms, cameras, sensors for water leaks, breaking glass, etc. Also locks and alarms. Outlets can be controlled by wall warts, or smart outlets where the outlet is directly controlled, or switches that control the outlet. Something new appears every month!
Getting back to you question, unless you want to be able to control the color of the lighting, and just want on/off/dimming, you can use the wall wart approach to get started.
