What is better to trade for volatility es or nq? If I can trade just a 1 lot which is better value?

Trading the Qs will typically provide more stronger moves to the up and downside. You may want to consider watching the market opens for both the NQ and ES to observe their behaviors and how the are correlated (Dow Theory). I wouldn't recommend going live in trading either one until you're running a "positive" SIM account.