>>48947695aiming for a certain pokemon is a great way to start. keep in mind that some are much easier/cheaper to collect than others (charizard, umbreon, most legendaries...)
bulbapedia has a great list of all cards by pokemon, including the cool japan-exclusive promos. for example, here's croconaw's :
https://bulbapedia.bulbagarden.net/wiki/Croconaw_(TCG)just search "pokemon_name (TCG)" and you'll find it