My advice would be to take the wheel to someone with some experience who will let you watch the process. If you want to make another attempt yourself, the first step would be to identify any spokes that are significantly different in tension from the average. You can do this by plucking the spokes and listening to the tone. Mark the high and low tension spokes on the brake surface with different colored Sharpies, then see if the out of true spots correspond to the out of tension spots. The goal is to have equal spoke tension and a rim that runs true.