Recommend using Envirolites and good reflector. Paint walls matt white. If you get on okay with first grow, then invest in HPS later. will still get reasonably decent yield. How I started.
Too early for nutrients. Still seedlings at mo. Leave until approx. 3 weeks old before adding nutrients. Leave your water sitting for a day, make sure it's room temp as cold can shock plant, use less nutrients than stated on bottle (usually about third). Pot size fine for now, but need more soil...