You need the Silph Scope from the Rocket base in Celadon City, that will automatically reveal the Lv 30 ghost as a Marowak.
You cannot catch the ghost in the Pokemon Tower until you reveal what it really is.
in pokemon tower in lavendar town
Work your way to the top of the Pokemon Ghost Tower and defeat the Rocket Grunts.
yes its really a Pokemon only you need a special item to see them once you have it go back and the ghost is now a Pokemon
Dark attacks. I suggest something common such as bite which a lot of the early pokemon can learn
Haunter.... There isn't that many ghost types in firered besides the Gastly line which you can find in Lavender Town's Pokemon Tower
Top floor of Pokemon tower in that purple city it's called. I dunno the level.
There is no ghost tower but there is a lost tower where you find ghost Pokemon on route 209.
By bike
There is no lost tower.
what about it? be more specific It's in the Northest part of Seven Island, across the water. All your opponents Pokemon are at the same level as your Pokemon with the highest level.
the Pokemon tower is in lavender town