You need to move everything to one side.
Subtract 2x on both sides, to get the equation 3y = -2x + 12.
Then, divide by 3 on both sides, to get y = -2/3x + 4.
Now we know that the slope is -2/3, and the y-intercept is (0,4).
Plot a point at (0,4), and plot according to the slope, then take the x-intercept plotted.