Hi Joana,
@clairejhi
Welcome to NGA!
The suggestions above for learning about the history, etc. are probably all you need.
I've only belonged for 2 years. I've seen very little "organization" activity. You can use the various features any way you want. If you explore the links you'll see there's more information than anyone could master in a lifetime. And it's increasing constantly. It's all there when you need it.
Members are generally happy to help with questions anywhere you are, just ask. Curmudgeons don't seem to dwell here.
One major benefit I've loved about NGA is these *moderated* forums. They're not obtrusive, but the (volunteer) moderators do keep things on point. No venom slinging here! And you can actually have a real conversation, unlike FB that hides posts and nests threads so badly that they're almost useless for actual discussion.
I don't know how the owner Dave pays for all this because there's never obvious advertising.
There's an internal inter-member messaging system called Treemail. Very useful. You can touch on a blue highlighted member's name and get options to send a Treemail or read their information.
There are "badges" which are the colored icons on the top of each post. Those indicate interests. You can obtain those by buying them with acorns. You can see an acorn symbol at the bottom left of the screen. Members can give you acorns and you can earn them in certain ways such as by adding images to the plant database. When you first submit some they'll be delayed while a moderator reviews them for meeting the guidelines.
As already mentioned, the plant database is one of the most useful features. I have an interest in daylilies. The daylily database includes all the information that is in the American Hemerocallis Society database -plus- additional images from members, links to all the "child" plants of each cultivar, and members' comments. You can note that you have any given plant, and see who else has it. This can be helpful in determining the likely adaptability to your conditions.
I recently discovered seed "swaps" which are organized here by members. It's a great feature.
Honestly I do not know of a better site to hang out! I hope you'll find it as enjoyable and useful as I do. There are so many ways to learn and in turn to contribute your own knowledge. Everything here is pretty much dependent on volunteers.
Pat