Complex sentence: In the fall of 2008, Little Big Town opened up for Carrie Underwood on her Carnival Ride Tour to support the album, before starting their first headlining tour in 2009 which began in January in Jacksonville, Florida and continued through April.
Split into simpler sentences: In the fall of 2008, Little Big Town opened up for Carrie Underwood on her Carnival Ride Tour to support the album, before starting their first headlining tour in 2009. Their tour began in January in Jacksonville, Florida and continued through April.