Amazon swords, java ferns, white ribbons are all really nice freshwater plants. Fairly easy to grow as well. I'm also a fan of the grasses. As for fish, there aren't a ton of freshwater or saltwater fish that will do well in that small of a tank. Off the top of my head, glow fish, any tetras, 1 beta unless partitioned, then 2, barbs like the tiger, or dwarf gouramis. With that being said, most of those are fairly territorial so you can't stock it very much. I believe theres also a few south american cichlids (small), and african cichlids (also the smaller varieties) that you can place in the tank. Cichlids tend to be very angry for no reason at all, and WILL pull up your plants and dig like nobodies business.
I have a 56 gallon fw tank stocked with a variety of oddballs, including SA and African cichlids. Most people will tell you not to mix the two because of the aggression, (much more so from the Africans than the SA). But if you do it when they are young and overstock your tank to spread the aggression, it will be fine.
In my honest opinion though, I wouldn't do much more than a smallish school of tetras in a tank that size.