Is my light too far away from my seedling? What sh...

Your light distance is fine and so is your seedling. As for how much water to give, give it half a glass of water every 4 to 5 days, once your media dries out

1. Your light is a good. 2. It seems to be growing well. Brown spot probably due to the substrate. 3. Cannabis plants are easily overwatered. For a seedling I would Water no more than one good watering every other day. You want to see the soil dry out before you water again. 4. Overall looks good. Best of luck mate happy growing 👌🍀

You medium is saturated with water from what I can see on the pictures aka the soil is too wet , so a soil too wet can block the nutrients absobtion by the plant and create a nutrients lockout so she's not or she'll not be abble to feed herself. The brown spots you're talking about are on the cotyledons , these spots are exactly where the shell of the seed where and sometimes it can do what you are seeing but it's not harmfull fot the plant and is not a sign of excess or def BUT if it continues to spread then my diagnosis could be wrong. To water your seedling you can spray the soil instead of watering it , the process will be longer but like that you can't really end up with a soil too moist except if your hands are heavy. Watering a sedling can be tricky as it's easy to over or under water at that stage so the only real advise I can give you is to not stick to a water quantity to water but to the soil , and don't water too often it could keep a constant moisture in the pot and slowing lean to on overwatering