Planning on buying a SteamDeck. What should I know before purchasing?

Optionally, what would you have wanted to know before you bought one?

Thanks!

Edit: Hey, thank you all very very much for your comments and suggestions, I really appreciate. I will most likely save up more and get the 1TB OLED model rather than the LCD model I was initially planning on. A couple of reasons for that, one, I am not good with electronics and I'd probably screw something up putting a new storage drive in. And two this thing will most likely be a permanent replacement for my old gaming laptop, which at this point is more than 10 years old, and seems to be on its last legs (I installed Linux on it, which was a struggle, but that is probably on me rather than Linux or the computer being at fault).

Anyway, I appreciate everyone's responses and thanks for helping a gal out!