If you have never kept amphibians, maybe you shouldn't start with darts. They can be problematic.
Perhaps one of the rubber frogs, Phrynomantis sp. or fire-bellied toads, Bombina orientalis is a better choice to start with. They are colorful and much easier to keep.
In the case of the rubber frogs, they may be a good trainer frog for those interested in darts. They eat small prey items such as fruit flies and bean weevils, so that will help to teach you how to culture small insects. And when/if you fail at that, they will eat small crickets you can get at your local pet store, until you have perfected you culturing skills.
Now the best beginner's frogs are without a doubt White's treefrog, Litoria caerulea and the gray treefrogs, Hyla versicolor/chrysoscelis. All three are tough, hardy species and are fairly easy to care for. Keepers of this frog soon find they have distinct personalities and enjoy their antics.