I’m using the same desk and chair as my home system, so I’ve got the ergonomics for that working.
The tech I mentioned in my response to the What’s your Tech thread @jesper referenced helps a lot - the items listed there are my standard go-tos.
In addition, I’ve got a laptop stand that’s simple and lets me position the laptop screen the way I want it, and a USB hub that makes sure I can plug in everything I need. The brand doesn’t really matter for those as long as it lets you work in comfort. For a webcam, any generic plug & play device will work if your laptop doesn’t have a built in webcam (mine does, although I don’t turn it on all that often - I’m such a raging introvert that voice-only works just fine for me most of the time).
I do recommend that at minimum you have a keyboard you’re comfortable typing with. I’ve never found laptop keyboards comfortable.
In my view, a temporary setup like the kitchen table is fine for the occasional day working from home, or even for a one-day-a-week setup. For anything more you want a decent and comfortable chair, and a desk that’s at a good height for you to work at.