2022-12-08 : A noncreature permanent that becomes a creature can attack and its {T} abilities can be activated only if its controller has continuously controlled that permanent since the beginning of their most recent turn. It doesn’t matter how long the permanent has been a creature. Notably, if you turn a land into a creature on the turn it entered the battlefield, you won’t be able to tap it for mana.

2022-12-08 : Kamahl’s last ability affects only creatures you control as it resolves. Creatures that come under your control after that point (including lands that become creatures) won’t get the bonuses.

2022-12-08 : Lands that become creatures retain any other supertypes, card types, subtypes, and abilities they have.