EA stands for Expert Advisors. I recommends you read this thread: TOP EAs
These EAs basically are programs that are going to monitor the market for you, find opportunities and even open positions for you.
Forex trading is the process of speculating on currency prices like EURUSD to potentially make a profit.
How do you trade it? You'll need an account under your name on a trading platform and funds loaded.
Keep in mind that one thing is making a trade and another thing winning a trade.