I started growing a few years back in soil and during your first grow you learn the most. I learned:

-when and when not to water based on weight
-how much light placement over the plants really does play a role
-don't start nutrient feeding until they are past seedling stage.
-how crucial a role air circulation plays with ANY plants.

Of course I learned many many other things but those were the biggies. To answer your question it probably took about a full 6 months before I knew what the hell I was doing.