Complex sentence: It was also the first Number One single for Big Machine Records (the record label to which Ingram is signed), as well as the first Number One for Jeremy Stover, one of the song's co-writers.
Split into simpler sentences: It was also the first Number One single for Big Machine Records, the record label to which Ingram is signed. In addition, it is the first Number One for Jeremy Stover, one of the song's co-writers.