Homie = homeboy, friend
Varrio = Mexican ghetto
Chula Vista = A place in San Diego
13 = Sureno, a Mexican gang that wears blue and identifies with the number 13, different from MS13 which is El Salvadorian.
Varrio Chula Vista 13 = A Sureno set (gang) from Chula Vista known for hardcore gangbanging
Blanco = white, and my skin is very white
Putting it together. I had a friend who used to gangbang with a Sureno set in San Diego. His mother shipped him and his brother up my way during high school to live with their father. We became friends and he named me Mr. Blanco because I'm so white you can use me for a tanning shield...note my forehead in the avatar. Before that people either just called me Scott, G because it's the first letter of my last name, Big because I was 280lbs. with 8% body fat at 6'5" in high school, or Big-O because I was big and really white like the Big-O tire man.
Oh but hell yeah, that big Sur side is everywhere up here because norte can't keep 'em out. Unlike SoCal where you won't see 14 anywhere below the San Fernando valley. Although, to be completely honest, most of the Surenos up here and just wetbacks staking a claim against the numerous farm workers. When they get tested they just say "no bang". My homie from VCV is one of the hardcore verteranos from back in the day before it became a hyna set.