If the hood has an incandescent lights, replace the light first.
Any moss will grow in low light. Some mosses are harder to grow than others, but still.
Be careful buying things are Petco and PetSmart. They sell stuff that is not actually aquatic. Go there, see what you are interested in, and then go home and search the scientific name if available and make sure it is aquatic.
This research will also tell you how to plant them. It is usually quite simple. However sometimes things are missed. One plant you make bury in your substrate, another may just have to be tied to something like a rock.
Otherwise most of the stuff they sell is considered easy. And don't forget, plants need food too. And do not leave your light on for too long.
Oh, almost forgot. Might want to get your Betta first and see how they are. I hear males can go from one extreme to another very easily when it comes to tank mates.