First temptation a new user will have is to go right for Rule Machine and whip up a new rule to control all their devices.
Try the other built in apps that are much easier, and most likely will do what you want without the complexity. Most or all of this can be done with Rule Machine, but RM is tougher, and maybe even slower in some cases.
Simple Automation Rules. This is a very easy way to just turn a light on or off with a very basic trigger. Turn a light off when a contact closes. Turn on a switch at sunrise. That type thing. It works exceptionally quick for these simple tasks.
Motion Lighting. Like the name implies, it is meant for motion triggering a light. I think it is a tiny bit more complex than Simple Automation Rules, but still not bad. You can use multiple sensors to keep the light on, and override the rule various ways.
Button Controller. Turn something like a Pico Remote into a device that can activate other devices. Push a button the light comes on. Push another the light goes out. Hold a button to raise dimmer level.
If you need more complexity, maybe then try Rule Machine. But in most cases, these other apps will what most users require.