Ok. Get some sand. If your old gravel is dry, then no bacteria is still in there. Id get a marineland penguin filter, with a biowheel. Id also add some decor, because the bio bacteria can grow on that as well. Decide now if you want live plants or not, if so, get a coralife t5 light (the brand is pretty low price, and I personally have and like mine) also research plants and what kind you want (possible co2 setup also) do you want salt water or fresh