Your plants look nice. I am first grower myself.
The one thing I noticed while growing my plants is that overwatering is bad for them, the leaves start to look unhealthy and it begins with the lower leaves. Now I check if the soil is moist and also i give them less water on cloudy days than on sunny ones. Now the plants are strong and healthy.
Regarding the spots on the leaves I can't say for sure, from the pics it looks like some kind of mold. is the room ventilated enough? the plants need some fresh air in there.
I'm sure that they will be ok.
Good luck on your grow!