If you are playing Pokmon Online and have some PTCGO codes, the first option sounds obvious as the most straightforward way of getting your hands on the cards above is by directly trading them one by one (friendly reminder: never open the packs you buy!)
When it comes to how to get these cards, there's a few options: obviously you can open packs, but you can also spend Pack Points to buy specific cards, or use the (not great) Pokemon TCG Pocket trading system to swap with friends accordingly
Each Pokmon card has a name, HP, type, attacks, and sometimes Abilities
I am going to make a point to only look at CGC listings as that is who I plan to grade with
Legendary Creature - Druid Merfolk Color tag templates(None) Trelasarra, Moon Dancer Whenever you gain life, put a +1/+1 counter on Trelasarra and scry 1