1. It is generally recommended to use natural gravel for the aquarium. Colored gravel can be used, as long as it is professionally made, certain cheaply made color gravels can be toxic to fish in your aquarium.
2. When breeding angelfish, it is normal for the first spawn to suffer heavy losses and not make it all the way to the hatching phase. You should have the proper equipment before you start to breed angelfish.
3. Cichlids tend to be very intelligent fish. You should do your best to interact with them as some species will respond positively to you arriving home. These fish are very active and if you interact with them, they can develop much better.