Hi, Welcome to aquariumadvice forum.
Well, You have some gold claw crabs with guppies. How big those crabs? Best advice I can give you is, DO NOT MIX the crabs with any other fishes. When they grow bigger they can scare the fishes and even eat them. So better remove them and have them in a separate tank.
You can try tetras or mollies with guppies. But watch the size of your tank. Do not overload your tank ever.