Do you sit at a desk and keyboard for multiple hours? If yes, please recommend a good chair.

I use a flexispot standing desk converter (it's like a big tray that goes on top of a fixed desk). I highly recommend doing so if you're going to be at a desk for hours every day.

My chair is nice af, and was provided by my workplace. If you can afford to go Herman-Miller (we're talking $1300+ for a new chair), do so. Your spine and butt and entire skeleton will thank you. Mine's an Aeron model