How do I clean an 8'x30" pool?

My boyfriend and I have an 8 ft 30 inch size pool and we have no idea how to clean it. The water seems a little green and the pool feels a little slimy and smelly. A friend told us to get some chlorine tablets. We went to Wal-Mart and we saw a bunch of stuff for swimming pool to clean it with. Is it necessary to get all those things like shock, Adelaide and all the stuff? Or can we use just one thing to poor in the pool that does all the work?