Head north on Island 1, and keep heading north until you see two rockets. You must have defeated the Elite 4 and gotten the National Dex.
lost cave
Go to Cerulean Cave. To get there, you must get the ruby and the sapphire and get the national dex.
the cave of origin is only in ruby and sapphire and emerald.
The HM move cut
it is in Mt. Ember
After you beat the Pokemon league, go to One Island. Go to the base of Mt. Ember, where you saw the 2 Rockets. They should now be standing in front of the opening of a cave. Beat them, go in, and go to the end of the cave, where you'll find the ruby.
trade ruby or sapphire
On island one, there is a cave with a ruby and a full set of braille alphabet.
You can usually find Pokemon like that in a cave.
It is located in Mt. Ember on Island One after you beat the Pokemon league. The cave that the rockets were blocking before is open for exploration after talking to Celio about the ruby and sapphire. After you get both, you can trade Pokemon Firered and Leafgreen to Ruby,Sapphire,Emerald,Colossuem and XD.
You cannot find Misdreavus in Pokemon Ruby. To get a Misdreavus you need to trade for one from a copy of Pokemon LeafGreen.
You find the ruby and give it to celio