Extra orders is a tool for averaging, adding positions (orders) when trading against the trend. Thus, open positions are averaged, and the take profit price will be recalculated so it will be easier to reach.
The level when another extra order is executed can be regulated by the “Step of extra order” function.
After I turn on the bot does it start trading immediately? It depends on your settings. If you don’t have any signals or filters, it will enter the market within a minute. In case you do have one or many filters, a signal bot will enter the market only when all conditions are met.
No filters - high deal frequency but more risk, as there is no market analysis.
One or several filters - more reliable trades as special programs are monitoring the market and allow bot to trade only when the market goes in your favor, but usually less deal frequency.