Welcome!
Good things to know as a beginner:
-Trust your gut about what you like. Even if everyone is raving about something, that doesn't mean you will like it necessarily.
-There's more to keyboards than just Cherry MX (or MX clones).
-All-metal keyboards are awesome, and you should own one, but they aren't necessarily the be-all end-all in terms of sound and feel.
-Always buy PCB mount switches; most PCBs have the holes to accommodate them, and, if they don't, you can easily cut the legs off. There's literally no point in buying plate mount switches. (The PCB mount legs prevent misaligned switches and make them a bit more stable if you didn't know).
-Don't buy stuff just because you are impatient. New group buys come up all the time.
-Don't be scared to sell something if you don't like it.
That's all I can think of.