Welcome smithmi!
In addition to the tips the others already posted:
There is no all over "master plan"... In the Main Arenas, pretty much anything goes... do whatever you feel like doing at the moment.
If you like joint efforts: Ocassionally there will be Missions posted and run by other players. When you partake in one of those, you "silently" accept the mission leader as CO for that sortie at least.
Aside from missions, there will always bee somewhat loose teamwork on capturing territory. Every now and then, youll see calls for assistance on country channels. If you follow those calls is entirely up to you though.
Youll soon find out that theres a whole bunch of "Wannabe Generals" - theyll try to order you around, usually in CAPS, since they are very very important. Youll get a hang quick of whats a "legit" call for help and whats not. Again, what you do is entirely up to you - theres no such thing as a "command structure" among players.