how do you find the 2nd password on four island and how do u open the ancient door on six island?

Answer 1

You use cut on the the door.

The second password is found in the bottom of the cave on island six. You'll need to head inside (use cut on the door) and fall into the holes in the correct order (one time each, four total times) and then you'll be met by a scientist at the bottom. He'll steal the sapphire plate and give you the password to the team rocket hideout on island 5.