If this land enters the battlefield at the same time as any number of lands your opponents control, those other lands are not counted when determining if this land enters the battlefield tapped or untapped.

Unlike some other dual lands, Turbulent Fen has two basic land types. It's not basic, so effects that search for basic lands can't find it, but it does have the appropriate land types for effects such as that of Necroblossom Snarl (included in the Secrets of Strixhaven Commander decks).