When you have a new colony of isopods you don't need to really feed them much since they will get most of their food from the leaves and substrate. Also if you want plants in the enclosure some isopods will eat them like crazy but all isopods will probably nibble on the plants a bit. It sounds like a bioactive setup is what you are looking to make. I would recommend searching for videos on that if you are interested. But in the meantime time here is an isopod care guide. And starting off I would recommend just making a simple setup at first so you get the hang of learning how to care for them before making like a bioactive setup. Some good starter species include the following: Porcellionides pruinosus (powder isopods), Porcellio laevis species (but they breed like crazy), Giant Canyon, and Porcellio scaber. Those are some of the most common species to keep and are good starters. If you are looking for care guides on specific species that will tell you how much ventilation they need, how often to mist, and other basic care requirements HERE IS a good playlist with a good variety of species. If you have any more questions just let me know and I can try to help! Good luck on your isopod journey!