Pila literally means "battery" or "pile". However, in many Spanish-speaking contexts, especially in slang and informal speech, it's used to mean "energy" or "a lot of something".
In the song, the line "Traigo pila pa' rato" means "I have energy for a while" or "I have a lot of stamina for a while." It's a common and versatile expression that adds a dynamic feel to the lyrics, implying readiness and endurance.
This track is a super blunt breakup song, but it's also a flex. Natanael Cano, a huge name in the corridos tumbados scene, teams up with Argentine producer Bizarrap to lay out exactly how much he's moved on from an ex. He's not sad about it at all. He says he's a completely different person now: "Por acá ya no hay rastro / De lo que conocías de mí" (There's no trace here / of what you knew of me). He's told his mom they broke up and now he has "dinero pa' tirar" (money to throw away) but no time to waste.
The whole vibe is about his new, successful life. He's hanging out with a rougher crowd and boasts that "Estamos de moda entre las de veinte" (We're in fashion among the twenty-somethings). The lyrics get brutally honest when he addresses his ex directly, telling her she was "una más del montón" (just one more in the crowd) and that she wasn't enough for him. It's harsh, but it's a powerful statement of leaving the past behind for a life of luxury brands like Burberry, travel to Argentina, and the attention of new women.