Congrats! If you're someone like me who owns a decent PC but no longer enjoys sitting in front of one, definitely get yourself a dock so you can hook it up to your TV. They cost around $30 and is a great investment. Just remember to take the casing off (if you use one) if you're planning to have your games running at anything between 1080p to 4K, and use FSR to reduce the load. I find the Deck heats up a fair bit even in winter.
Owning a Steam Deck really got me back into gaming. I carry it to work to play during breaks and hook it back up to my TV when I get home.
This was my motivation for getting one. I work from home, and my work laptop and my gaming PC share a desk, thanks to a pair of KVM switches. Sometimes I don’t feel like spending my evenings in the same chair I spent the day in, and enjoy flopping down on the couch with the Deck in handheld mode.
Pretty good as long as I stay in the shade, but there is glare which is when an antiglare screen as others have mentioned comes in handy. I don't have that screen though but there's matte screens that can be tried out.
And! Enable wlan and get an app on your phone to power on the decent computer with. Get game streaming working. And now you play the demanding titles on the Deck through your computer in handheld with good graphics and enormous battery life. Also get something like parsec to be able to log on and power off the computer. Never need to sit Infront of it ever again? That's my life :)