Where to start?

[smoki]

So... I get Hyperlobby, update 1946 to the newest patch, and that's it?

How do addons affect multiplayer?
If I don't get the most popular and biggest addons I assume I won't be able to play the matches that utilize maps, lets say, or aircraft, from those addons?

Or will I be able to join any match but those elements I don't have will be switched to something i do have? Sorry, I'm new to this whole multiplayer business.

The point being, I just need to know: I just need to patch up, and not "addon", and I'm good to go?