This is one of the most common questions new collectors ask. The honest answer is that it depends on what you want out of the hobby. If you just love Pokemon, collect what makes you happy. Maybe you want every Pikachu variant ever printed. Maybe you want to complete a specific set from your childhood. Maybe you just like pulling packs and seeing what you get. There is nothing wrong with this. Most collectors start here, and many stay here forever. The hobby is supposed to be fun. If you are stressing about market value on every card, you are doing it wrong.