OR you could download Warbirds for free from iEN and practice offline missions and duel with any plane you choose against any plane you choose, or numbers of them, offline, forever. The graphics are inferior, but practicing against something that shoots back is a lot of fun, and it will help your gunnery a lot. Plus, if you set the AI fighters to the highest skill settings, your victories will be few, your level of frustration will be highest, and you will learn real quick.
This is not to advocate flying Warbirds online. It is definitely the inferior game, but until AH comes up with practice missions for newbies or vets, Warbirds is REALLY good for offline practice, and it is FREE.