Mode 2 is used by nearly everyone in the US. In this mode ailerons and elevator are on the right stick and throttle and rudder are on the left stick. Mode 1 swaps the location of throttle and elevator. If you are flying in the US and haven't already learned a different mode, it's best to stick with mode 2 unless you think you will never want to have someone else fly one of your planes, or visa versa.