First Appearance of Trainer Cards The Base Set introduced essential Trainer cards like Professor Oak, Bill, and Energy Removal
As more expansion sets get added, it will be interesting to see if you can trade cards between sets and across expansions, provided they meet the requirements
Also, some have noted that, while Pokemon TCG Pocket has featured creatures from every generation of the franchise, the first two card releases have put a significant focus on those from the Kanto region (as seen in Pokemon Red and Blue )
Identifying a Cards Rarity Look at the expansion symbol on the right side of the card, near the illustration
Id recommend leaving the Monoliths behind and instead run a lot of cards that nobody plays because the activation cost is too expensive
There are more great pickups here than you can shake a Kessig stick at, but the following five should give you the most bang for your buck