Spread is differences when you buy or sell. In other words, we can said the diffrent in between the actual price and the buying or selling price. For example, USD/JPY you bought at 1.4529 and the actual price is 1.4527, in this case, the spread will be 2 pips.
Does all pair has the 2 spread pips?
The answer is no, depending on currency that you buy as will as the liquidity. The highest the liquidity the smaller the spread will be and the other round for lower liquidity currencies.
My advise is not too worry about the spread, as long as you have the right stratergy, eventually you will cover back your spread if there is a winning trade.
What are the important terms that we need to aware:
As long as you can understand those, then you are good to trade with live account too. Always start with a mini account first before your get involved more and more capital.