the first taste - edit 2

[Lizzie]

The First Taste
 
Warm Virginia pine trees reaching the sky,   
mountain bikes on the neighborhood pavement,
beer from dad’s garage stolen on the sly,    -- The first three lines work well for me to establish the scene. I'm there with you.
twelve-year-old boys after adolescence.      -- I think you mean that the boys are in search of adolescence? Maybe you could say reach for, search for, etc.
Into the woods we’d take a path to hide,
and sit in a ditch near the railroad tracks.
From a school backpack, we tore open wide 
unveiling cans cooling hands that instant.
The cool fizz blew open the can’s insides,       -- This line and as well as "tore open wide" seem like aggressive, racy imagery. Intentional?
and showered out a fit of shaken spit.         
Dumb, I glanced at my friends with no reply
and drank the rest, a half at best, half fizz.
Pretending drunkenness back swerving bikes,
we pretended the adults of cursed life.            -- I understand the meaning of these lines, but they read awkwardly. I agree that the form of the poem needs to give a little here.
And now, without the courage to pretend,
I still swerve the road looking for the end.