If you want to learn forex perfectly you can trade n a demo account. It has no risks. You can learn all the basics of forex easily from that demo account.
Success in the forex market mainly depends on the knowledge and experience you have. The more you have knowledge on forex, the more it is possible to earn money from this market.
Yes, you are right. Most of the traders lose their money because of their greed. If you can control your greed you can make money from this market, and can become successful in the forex market.
Knowledge is the main important thing in the forex market. Without knowledge it is quite impossible to make money from this market. Beside knowledge, you also need a good and reliable broker to trade in the forex market.
Minimum investment depends on your trading ability and knowledge of trading. If you don't have enough knowledge about trading, it will be better to invest little amount first to justify yourself.
To start trading, you need a good broker, A good plan, A good trading strategy, Courage, patience, risk taking ability, and the most important basic knowledge.
Broker is the main element to trade in the forex market. Most traders lose their money because of choosing wrong brokers for them. So, be careful when you are going to choose a broker for you.