For beginner turns you should start with even weight on both feet in a balanced body position. Think knees, ankles, hips slightly flexed and your upper body straight and in line with the snowboard.
Say you are starting on the heelside, perpendicular to the fall line. Release some pressure of the edge so you start to side slipping down the hill. Pressure the lead foot slightly to initiate the turn. Rotate the hips, and maintain upper body alignment with the snowboard. Allow the snowboard to approach the fall line, and continue to move through the turn by rotating the hips through the turn. Flex the lead knee and ankle to engage the edge. Return to balanced, even pressure of both feet as you traverse the hill. Repeat for the next edge.
TL;DR : Pressure the front foot (roughly 60%), rotate hips (center of mass) to initiate turns.