A demo account is a live simulation. So it mimics live prices very closely. They do have a slight difference at some points in price as well.
You are absolutely right that here traders can make frequent mistakes at the initial level so they should try to accept the mistakes. Again welcome you to the forum. and you will definitely enjoying currency trading, but please try to work with demo trading accounts so that you can get the acquaintances with the basics of forex trading without taking any risk. And once you get full confidence, I will suggest that, you can work with major pairs with mini accounts as a scalper.
Yes, every trader has done so many mistakes in their trading life. But learning from their mistakes is also a good way to be a better trader with the positive mind towards trading.