Final answer:
In 'The Cheetah Girls 3, One World,' the first song performed is 'Cheetah Love.' This sets the tone for the movie, emphasizing themes of friendship and unity.
Step-by-step explanation:
The first song they sing in The Cheetah Girls 3, One World is Cheetah Love. This upbeat song establishes the theme of friendship and unity that runs throughout the movie. While all the options given are songs featured in the film, Cheetah Love is the opening number performed by the girls.