Simple stuff to prevent you from panicking early on:

• Say you’re playing docked with an external controller and you put your steam deck to sleep. After it wakes up the next time you use it, 99% of the time, the game won’t respond to the controller input anymore. You need to reorder the controllers in the menu and it’ll come good again. Only in extremely rare cases have I had to restart the game.
• Less so now, but early on there were definitely cases where I had to power cycle the steam deck because something went wrong. Even if the screen is black for a bit, just give it some time.
• There’s years of tips/tricks or software mods that people have collected that may/may not be relevant anymore. Just play it for a week or two before tweaking things. For instance, I love Decky loader for adding things like protondb support and how long to beat times to the library… but you definitely don’t need it.

If you do decide to play docked, Sony Dualshock 4 or Dualsense 5 controllers are great because they have touchpads. This makes them super useful in games with half implemented controller support (i.e. the games work fine but the menu controls still use a mouse) or using desktop mode from the couch. They also have gyro support too.

I haven’t had many issues with PC usb-c hubs… but all hubs are created differently. If you care about 4K output, VRR, HDR or anything about basic usage, I found a dedicated jsaux docking station works pretty well (note: I never considered the official dock as it was only officially available in my country well after I already had a steam deck).