When I was first timer, I made mistake of over-trading and that was mainly down to excitement, so I will say the best thing new comer do is practice on demo account and get use to trading. Once we are settled in trading than we could move towards real account which will help us keep control of the nerves and currently I have followed this way only with help of OctaFX broker especially with their cTrader demo contest where there is huge prize up to 400 dollar to be won.