You will get an email notification once membership is approved (if you don't see anything after a few hours or so, check your junk email filter/folder - the emails come from "email@example.com").
When your application is approved, the 'Your Story' and 'What do you want to gain from this forum?' portions will be viewable in the forum. This will give everyone some basic background on your journey and current situation; it's a good starting point for getting involved in the forum. Only registered users will be able to see your user name and forum activity; no one will see your email address unless you choose to share it.