Low light plants that would be good for you:
- Java fern
- Water wisteria
- Water sprite
There are a lot more, but these are pretty easy to find and super easy to grow. All of those except java fern can just be left floating in the water if you want to. None of them require any special substrate - I have them in gravel, sand, and special planted substrate and they are all fine wherever. You also don't need any fertilizers with any of them, although you can add a weekly or twice a week dose of Seachem Flourish, and it will help them out.
Java fern and anubias can both be attached to rocks or driftwood very easily. You shouldn't bury the rhizome (nodule thing where the roots grow out of), but you can weigh the roots themselves down with a small rock or you can tie them to something with string or fishing line. I actually have some anubias zip tied to some of my ceramic decorations in one tank.
I have found java ferns, anubias, and wisteria all in those tubes at Petco. A website I would recommend also is http://www.tricker.com
. Almost all the aquarium plants they sell are low-maintenance and don't require anything special. Another good resource for inexpensive plants is the classifieds section here!
One tip I wish I had known/done when I first started planting is this: don't worry overly about "aquascaping" when you first start. Put the plants in and give them a week or two to see how the plants grow in your tank. Once you see what does well with your water chemistry, pH, hardness, etc., then think more about arranging a specific scape or theme. It's sad to put a bunch of work into making a tank look fancy and manicured only to have something die and another thing grow uncontrollably and then have to change it around after a couple of weeks