JuiceBox52 covered it pretty well.
Acarichthys heckelii are a bottom dwelling fish that need a substrate. Without that they stress. The same with the background, they need a picture on the back of the tank if you don't already have one. And some real or plastic plants would help too, including floating plants.
After that, the fish needs time to settle into the tank and some companions would help. The companion fish can be any fish that swims around and helps the cichlid feel more secure.
Albino A. heckelii aren't very colourful and if you want the most colour from this species, you should get a normal coloured fish. However, if you prefer the albino version then that is fine too. But the albinos prefer a darker tank than the normal coloured fish. Use a dark substrate, dark background, lots of floating plants and or minimal light.