G'day Mate,
You have paid your money for a computer radio, you might as well use the functions it provides, go through your manual, step by step, with reference to the pages that show simple setup for acro plane with 2 aileron servos. Learn as much as you can about the radio & it's functions, this will stand you i good stead, when you need to know how to change anything.
But don't go the slack route & settle for a Y lead. You will find sooooo much more fine tuning available with separate servos on separated channels.