My First Terrarium (La-La-La-Laaaaaaaaaaaaaaa)

I've been very interested in gardening and plants all my life, but started getting serious about it for the last couple of years. Living in a third floor apartment in Brooklyn, though, can be difficult when you actually want to get your hands to get dirty. To begin with, plants are expensive. You'd think they wouldn't be because they're plants, but at a shop near my apartment a philodendron costs $25.00! Then I have to make sure that any plants I get are pet safe because of my cat Bart. And, of course, there's the tendency my plants have of dying (no matter what I do to keep them alive.)