Did you get any paper work with the light. If you do it may tell you where to start. If not look on line google or what ever. Just put in your lights name and size, good luck.
whats you wattage ? example a 240 watt led (seedling stage 30-36 inches (50% power) after 2 weeks gradully increase power to 75% at 24 inches and then flower at 16-20 inches at full power --hope this helps ! it takes a while to understand led lighting because of the light intensity of .