IanB hit the nail on the head so to speak. After 50+ years of experience, I still take extra precautions when I have to deal with anything that has exposed mains voltages.
I don't know if it is necause of experience, knowledge, wisdom, or just becoming a bit more risk adverse as I get older, but I find that as I've gotten older, my desire to bring mains voltage anywhere near my circuits has decreased drastically.
Some of my early experiments were computer controlled lighting controls, assembled with great ignorance. I'm surprised I didn't burn anything down. I still have one assembled carefully in a wooden box with inadequate standoffs. And no I don't use it anymore. It's simultaneously frightening and also amazing that I succeeded in making this work.
For the OP: there are lots of interesting projects out there which don't directly connect to the mains, and instead connect using a certified power adapter, such as a USB charger. In fact a couple of the projects you described would work this way.
For instance one can buy pir sensors which would run off 5V which is USB voltage. You can also buy safe relays to control with them or with other circuits (look up DLI IoT relay).
The LED light array also wouldn't need direct AC connection.
I'd just skip anything which connects directly to the AC line.