You are probably not going to like this but here is my answer to how many trades it takes: If you still have to ask, then it's still not enough.
Only you will know how many trades it takes and you won't know that until you feel truly comfortable and confident in taking them. No one else can even give you a good hint.
One other thing... Most of it has to be real trades with live money, even if it is a single contract, or it won't mean a darn thing.
The road to trading success is littered with the bodies of thousands of failed traders who made hundreds and even thousands of demo trades only to have their confidence irrevocably shattered when finally making the switch to having real money at stake.
Learn about and observe the instrument you are going to trade to get a good feel for when and how it moves, select the timeframe that matches your own personality, trade demo til you are truly proficient at executing trades on your chosen trading platform and then switch to live money and one contract until you get your emotions under control, regardless of the strategy you decide to trade.
Happy Trading
