Qué chimba is a very popular Colombian slang phrase, especially from Medellín where J Balvin is from. It's an enthusiastic expression that means "How cool!", "Awesome!", or "So great!".
In the song, J Balvin uses it to admire his partner, singing "Qué chimba de cuerpo y de cara" (What an awesome body and face). While the word chimba can be vulgar in other countries, in this context it's a high compliment. Learning this phrase is a perfect way to dive into the unique slang that defines modern reggaeton.
J Balvin is celebrating a love that completely changed his life. He thanks heaven for his past mistakes because they led him to this person, saying, "Me devolviste la fe" (You gave me back my faith). It's a sweet and very direct song about finding 'the one' and settling down. He says his friends can see the change in him—"El brillo de los ojos se me nota" (The shine in my eyes is noticeable)—and that he's even given up drinking for her: "He dejado el whisky por usted" (I've given up whiskey for you).
He's found everything he needs in one person and has no desire to look for anyone else. He asks, "¿Pa' qué buscar en la calle / Lo que abunda en mi casa?" (Why look on the street / For what is abundant in my house?). He sees his partner as the total package, praising her personality and her looks. The song describes a relationship where both people healed each other. He was her comfort, "Yo fui ese hoodie que te quitó to' el frío" (I was that hoodie that took away all your cold), and she was his, "Tú fuiste la cura cuando estaba despechado" (You were the cure when I was heartbroken).