for new trader i think the best pair to make learn is eur-usd, this pair are suitable for learning because it have consistent and not to big movement also more stable in movement and for sure this make us more easy in understand the market price movement. but for sure any pair we use for trade can be good if we have skill to trade on it, this the same with eur-usd if a trader have no skill for sure eur-usd will cause huge loss