@Bosgeng: Is a demo account really that important?
It is important. Demo accounts are intended as a place to practice until we are confident we are ready to trade before using real funds. If you can't profit using a demo account, it's very likely you won't be able to profit with a real account either. Even worse, if you're still getting margin called (MC) on a demo account, it's very likely the same will happen with real funds. Be patient and practice with a demo account until you are confident you are ready to use a real account. This way, we don't need to experience losing a lot of money due to MC on a real account.
How long should you practice with a demo account before opening a real account?
It depends on the trader. If the trader learns from a mentor trader who has consistently profited (imitating the mentor's system), it usually only takes 6 months - 2 years to become consistently profitable. However, if the trader learns on their own and creates their own trading system, it could take 3-5 years.
It's important to understand that it's not the trading theory that's difficult to master, but rather the aspects of mindset, psychology and money management. Many people struggle to be consistent in the market because their mindset is wrong, their MM is wrong, and they can't control their emotions or are not disciplined. I myself struggled with MC for years because I always wanted to get rich quick, ignored money management and was always emotional about entering the market even when I shouldn't have.
After being able to overcome the aspects of mindset, MM and psychology, my trading became better. To be honest, the learning curve of trading is very difficult. Big profits and consistent profits are two different things. Many people can make big profits in the market at one time, or for a few months, but very few can profit consistently in the market.