Need help or advice on reading markets XAU/USD

Hi, I’m New to trading and I realised gold have plunge to 1200 level in a single candle stick. There aren’t any major good news and I wonder why did it happen this way?

I notice gbp/usd went up slightly but the sentiment were so bearish then it plunge downwards nearing the exit from EU. How does one actually improve its skills on reading markets?
I’m currently practicing on a demo account for my trade plans.