If the target land hasn’t been under its controller’s control continuously since the beginning of their most recent turn, that land won’t be able to attack and its {T} abilities can’t be activated. In most cases, that means it will no longer be able to be tapped for mana that turn.

Ignition Team’s ability doesn’t affect the land’s name or any other types, subtypes, or supertypes (such as basic or legendary) the land may have. The land will also keep any abilities it had.

Copies of the affected land won’t be 4/4 red Elemental creatures. For example, if the target land is a basic Mountain, a copy of that creature would just be a basic Mountain.

Effects that modify power and/or toughness without setting them to a specific value (like the one created by Giant Growth), power and toughness changes from counters, and effects that switch a creature’s power and toughness will continue to apply. This may happen if the land was already a creature when the ability resolved.

This doesn’t count as a creature entering the battlefield. The land was already on the battlefield; it only changed types.