Just FYI to determine whether your tank is appropriate for a DG - the article recommends no less than a 2ft long tank so it has swimming space and only house it with non aggressive fish - a pair is not a good idea.
Java moss I believe is a low light plant so you don't need anything special for it, however, the fish need light for a few hrs each day so you would need a light for the tank - you will also need a heater & thermometer to maintain a consistent temp.
46 gal fw tank with black skirt tetras, neon tetras, spotted corys, cherry barbs, otoclinus, snails & 4 amano shrimp - plastic & live plants
5 gal QT
Remember: Our job is to take care of the water our fish live in