A demo is a must for any newbie. You would lose less money if you practice a lot in a demo. You would be kidding yourself to move on to a real account without practicing a demo first. You will learn all the technical there and you will learn how to avoid mistakes. If you made all of your mistakes in a demo, you won't make them in a real account. If you go to a real account, you will be sure that you will lose all of your first 20 trades due to little technical mistakes.
like when looking at it from another perspective we will have to see that forex demo trading is however no a must as newbies can still chose not to trade entirely with the demo account. But I can say that it is essential for anyone who wants to make money in forex trading.