Risk % is the percentage of your Account Size that you want to risk on your Trade.
Most Traders risk between 1% - 5% per trade, however, when starting to Trade, it is recommended that you risk no more than 1% per trade, until your experience and results indicate otherwise.
Risk % does not equate to the size of your trade, it is simply the value of your Account Size that you are prepared to lose, IF your analysis is incorrect and your Stop Price is hit and your Stop Loss order at the Exchange is triggered.