The main thing IMO is to get some hands on time with it. Figure what you want, what you like, and most importantly what you would like to see improved… and go from there. See if you prefer to use it as a console, or if you want more of a gaming computer and use regularly the desktop. Maybe you’ll want a dock and how you want it will depend on your needs. You get my point :D
Anyway for the laptop see if you like https://nobaraproject.org/download-nobara/ specifically the Nvidia one so it has the drivers pre installed. I use it “everywhere”
A thing about the official dock, maybe it’s just my setup BUT: it drains the battery. It doesn’t look like it, but if it’s off or suspended, the Deck loses charge while connected to the dock, then you grab it to use it (and the battery is like 97%!) but within 5 minutes it’s completely dead. Again, it might be just my setup, but now I unplug the Deck from the dock once it’s off.