Welcome to Tropical Fish Keeping forum.
I have the same tank (one of my 7) with the same light fixture. Photo below shows it presently. I would replace the tube, the one that comes with these tanks is less than good when one has plants, and the colour rendition is purplish too. You can get a decent tube in a hardware-type store, you will want a 24-inch tube in T8 (T12 is OK if that is all you can find in this length but the T8 are better), with a Kelvin rating of 6500K. GE, Phillips and Sylvania make these (though I can't say all make them in 24-inch length) and they cost a couple dollars. If you don't mind spending more, you can buy tubes from a fish store that will be more expensive. Good ones are the Life-Glo 6700K, and the ZooMed UltraSun 6700K.
Java Fern and Anubias are both low light plants, and both should be attached to wood or rock; don't bury the rhizome in the substrate or it may rot. Water Sprite, if it is Ceratopteris cornuta, is best floating.
You will note that the plant names shaded, so you can click them for the plant profile. We have profiles on fish and plants under the second tab from the left in the blue bar across the top of the page.
One suggestion on the fish; don't get 10 Bleeding Heart Tetra. This is one of the largest tetra species, and it needs more space than a 20g, and it will outgrow the water volume too. There are some similar tetra like the Rosy Tetra and Roberts Tetra, and many others more suitable. Browse our profiles.