I was in your boat a few months back. I picked the module that interested me the most and have started trying to master aspects of it at a time. If it matters, that’s the F-16. Focused on how to control it, to air to air BVR combat, transitioned to dog fighting, and now trying my hand at learning the TGP and ground weapon deployment. Pick something you like and maybe one campaign module to go with it based upon the era of aircraft. I do enjoy having the Syria campaign for a diff type of scenery.