What started out as a 14-year-old’s dream has shaped up to be a fun musical journey — and it’s only just taking off. Justin Cheromiah began recording music in his bedroom at his San Bruno home, releasing lo-fi singles online. Three years later and only 17, Justin has produced more than two dozen songs as the frontman of his dream pop band, High Sunn, which released its first studio-recorded EP, “Hopeless Romantic,” this year.