I would suggest you go live right away as part of your testing instead of using a demo account, but with a broker that allows you to trade micro or nano lots (10 cents/pip or 1 cent/pip). Demo accounts sometimes act differently than live accounts ...

I created a system, what next!?

I would say if you can trade a few hundred million during the start of the asian session, you might be able to move the market just a wee bit.

At What Point Are You No Longer the "Fly on the Back of the Elephant"