Good question! So first and foremost, cards serve as a “spark table” that can be interpreted in many different ways (think tarot reading). One of the three characters you are tasked as playing is “The Road” whose goal is to connect the story. Like a tarot reading, some cards have obvious meanings, and some are completely recontextualized by the next drawn card. Do not feel pressured to stick with your decisions, the beauty of solo games is that you can retcon.
So for example, drawing a support card featuring a named human. If the card right after is an item card, then maybe they are an old friend who gifted you an item. If the card right after is a Pokémon, then maybe they are a trainer who is challenging you to a battle (you cannot catch their Pokémon). And I should note that just because you draw Pokémon doesn’t mean it has to be a battle. If it’s the next stage of one of your Pokémon, maybe the booster pack is telling you that your Pokémon evolved!
Long story short, the cards can be interpreted in any way you like. If I you’re having trouble interpreting a card, consider drawing again to add context, or maybe ignore the subject of the card entirely and focus on the background in the art.