It is not illegal to collect drift wood as long as you don't saw pieces off the existing trees in the surf. Unless you are going to the Keys there's not a lot of rock on the beaches. There is rock in the intercoastal that was placed there for erosion protection, but I would never place it in a tank even if you bleach it. I also would not place drift wood in a SW
tank, that is for fresh water applications. Face it you either need to buy balas rock from a LFS
or buy coral, both will cost you. I also remember reading you bought two fish for $17, that is cheap, quality fish go for $50 to $100, and if you don't understand filtration and lighting you will spend more money on fish than rock.