Hi Pia,
it might offer little help but encounters like this are really rare. But IMO thats great because in reality there were not often even odds. Germans fought at best 1:40 in 1945, in the beginning of 1942 unexperienced US pilots had to fight veteran Japs. They hadn't much fun I guess but many survived. For me (and many others) beginning in this game was also very hard. Actually I threw my mouse (wireless) out of the window (2nd floor) once - it had no ED so it lies on Arlington now. But believe me, there will be a time when you know how AI is working and then will you be disappointed when you only score three kills in a mission. So keep trying, you're really not alone in the skies.