I also started with collecting just this past month. I had been eyeing the Mythical collections and saying to myself, that's going to be something I want to get, the 11 mythical pins and cards, and the set that comes with them. I had to then add the Red and Blue collection to my shopping list. I'm extremely interested at this time in when all of the items release in Canada. I've never followed TCG before, so it's new to me. I also decided to get the Mega Diancie set just because I could.
I did also pick up the Mewtwo and Darkrai battle decks and the Mega Diancie pack. The decks have already been broken into their respective sets, and are not in deck format currently at all; all energy cards for both decks currently reside in one box with the portion of the XY and Flashfire booster sets (the first two) so far, and all BW booster cards are in a single sorted (by release) set and elastic-wrapped (as I do not expect or plan to build this collection), though I may pull the theme cards out if I ever build a deck. Phantom Forces is currently elastic-wrapped (two boosters packs from the Mega Diancie set) and includes a holo Diancie, ironically enough; meanwhile, Furious Fists is boxed with the Generations pack I have so far, as well as some other miscellaneous XY cards (the Mew and Diancie promo cards currently live in there). I've decided I can use the TCG itself to look up all of the individual cards and holos and thus be able to track not only the TCG numbers, but also the ones I own physically by knowing exactly what kind of card is possible for each number in the deck. I've since created a collector's sheet for the first six XY expansions (up to Primal Clash) and then skipping to Generations. When I get my next booster box (looking at Pikachu-EX or Hoopa-EX, maybe both for all the promo cards), I'll be doing a proper cataloguing of all booster cards to date.
So yeah, I only collect, but I'll eventually use the spreadsheet to help me trade in the online TCG and eventually expand that collection. Code cards will help this task, as well.