A way that you can practice the multiple enemy scenario is offline using the drones. Concentrate your attack on one plane, and use the .wingman command to highlight a second plane, pick a plane close behind or around the one you are concentrating on. Attack the one you are concentrating on but every few seconds switch your view to the plane you have wingmanned. Once you destroy the first plane, switch your attack to the wingmanned plane. If you want to continue, after destroying the first plane and switching to the second, wingman a third plane and continue. A progression of this technique would be in the TA with a couple planes that maneuver as planes would in the MAs.
There may even be offline missions you could use to help.