Following in his parents’ footsteps! Gwen Stefani and Gavin Rossdale’s eldest son, Kingston, made his debut at Blake Shelton’s Ole Red bar and music venue in Tishomingo, Okla., on Aug. 11. “I’m actually honored to be the first one to introduce this guy to the stage for the very first time ever,” the country singer, 47, said of his 17-year-old stepson. “First and foremost, this guy is an artist. This dude is rock. I don’t just mean he rocks, like, his music is rock.” Taking the stage, Kingston performed several songs, earning a round of applause from patrons as he showed off his vocal range. A source says the gig was a huge step for the teenager and that having stepdad Blake and mom Gwen, 53, there cheering him on…
