Apistogramma cacatuoides are a good beginners fish if you get local bred stock. If you get wild caught fish they can be difficult to settle down but stuff from Germany or fish that have been bred by someone in your neighbourhood are tough as old boots. Well not quite that tough but they are quite a hardy fish.
Local bred stock will survive in a wide range of water conditions including a pH between 5.5 - 8.5, and they will tolerate hard or soft water. They eat most frozen and live foods and many will take flake or sinking pellet foods. They make great parents and breed readily in caves or under rocks. The babies are easy to rear on newly hatched brineshrimp and you can generally sell any young you produce. They do best when kept in water with a temperature between 24-28C but tolerate 22-32C.
The only thing you really need for them is an established filter (fully cycled tank) and clean water, which can be accomplished with regular water changes.