I'd recommend lurking.
No, for real - whenever I've tried to pick up a new metagame, the first thing I do is just read random threads in the metagame's forum for days trying to get a feel for what's good and what's bad, then eventually ask other players directly for help building teams. I understand it's a lot different in my case than yours, since I've been playing forever, but I can also apply this to League of Legends - I'd have literally no idea what I'm doing in that game if I didn't read up on it a ton (ignoring the fact that I'm still pretty bad, that's my total lack of mechanics and micro understanding). I've never found guides particularly useful apart from the really old school Smogdex analyses, I'd rather read raw discussion and see multiple people post their opinions.
If after reading up on how other people see the game, you're still totally lost, I suggest you check out the
Battling 101 forum and consider signing up for tutoring. Also feel free to send me a message here or on Pokemon Showdown if you have any questions!
If you're willing to be sucked into Doubles OU that's cool too