Forex trading does not always generate a certain amount of income and may even generate certain losses consistently. It may be one of the reasons why many traders quit the market. If the trading is successful for a long time and the profit increases, then you should decide to choose forex as a profession. Also, choose to trade with a regulated broker like Eurotrader if you want to be a professional trader.
There are lot of currency pair in forex market. But I prefer to trade in major pair like EURUSD, GBPUSD, USDJPY. They are quite volatile than other currency pair. Moreover, my broker Tpglobalfx provides low and tight spread in major pair. I am scalper, So, I need low spread for my trading strategy. However, trader should trade in all pair. Mastering one or two pair is enough to become successful.