First Grow

My friend found a single seed and gave it to me just to see what i could do with it. So i planted it expecting nothing and now it is around 10 inches tall. No idea how old it is, (thinking around 8-10 weeks). Once it didnt die after the first few weeks i started taking more care of it and researching a bunch of stuff. Right now its in a 2' by 2' area with 5000-6500 lumens on it from 3 CFL bulbs. Im not expecting much yield because this is just something im doing for fun. Its in a 3 gallon pot with 18/6 lighting cycle. I was wondering when to switch to 12/12 for flowering and how to tell if its male or female. I have since acquired 9 more seeds and hope to do another more serious grow soon. this was just a test run i guess. Not expecting much but still excited!
Thanks, Sanctus Vita.

Is it looking healthy so far?