If you want a longer explanation, let me know. Placing 4th (or higher) in tournaments ('Events') is probably the best way to earn tradeable booster packs. Know that unopened booster packs are the 'true' currency of the PTCGO for this reason. The best way to get what you need in the PTCGO is like real life buy/trade for it! You can't really 'buy' here, though, so trading it is. However, if you're really new to the game, you're best off sticking with the Theme Format for grinding rewards, anyway.

Only a few Theme Decks have proven good starting points for such a thing over the years. The less short version is the same, but making sure you know that you probably won't get an overly competitive deck if you use Towering Heights as the base. As you also like the Pokémon it contains, that means it should be a worthwhile purchase, and make grinding for rewards in the Theme Format easier. I don't know if it is the best Theme Deck in the Theme Format, but when I used it, it seemed reasonably good. The short version of my advice is yes, go ahead and buy Towering Heights.

I'm a bit rusty on the Theme Format meta myself, but I have played some since Towering Heights and Unseen Depths were added.

Pokemon ex in every pack