Serena is a new trainer who is just starting her journey. She has been living her life to become a Rhyhorn racer like her mom, but isn't actually interested in the profession. When she saw Ash on TV whom she recognized from her childhood, she decided to set out on a journey as a way to get away from Rhyhorn racing and to reunite with Ash in order to thank him for helping her in the past. It's heavily implied throughout the show that she has a crush on Ash, blushing at many situations when someone points it out.
She is interested in fashion. Due to this, she became interested in the various PokéVision videos.
Fun fact trivia:
She's the first girl to know Ash prior to the show starting.
She's the first girl to not get violent/get into fights with Ash.
(Spoiler episode 47) After Shauna introduces Serena to performances, she pursues becoming a Pokemon performer.
(Spoiler episode 138) After her performances in the Kalos region showcases, she heads to the Hoenn region to enter Pokémon Contests.
Pokemon has always featured Satoshi (Ash) challenging Gyms to win badges and enter the Pokemon League. But Gym battles are not the only path open to a Pokemon trainer. Aspiring, young trainers can also work hard to win Showcases, Contests, and a number of other events with their Pokemon partners.
