If the seed hasn't popped then you don't need light at all. After it sprouts you will have to experiment. They don't need much light at the beginning,, 18 - 24 inches seems about right.
Your light will flower 1 small-ish plant in 1.5x1.5 space.. Don't believe the Chinese manufacturer's claims. It's an ok starter light though. Should work fine if you don't expect more than it can deliver.