Birding allows you to take it as seriously as you want it. Some people only bird from their backyards well others chase birds that are hours or even days away! Both (as long as done ethically) are great. But those are the extreme ends of the spectrum most people fall somewhere in between.
Well there isn't really a hierarchy. Some people that have been birding for decades or who have studied a lot are very well known for various things in the birding community that can be viewed as stories of celebrities, people such as Ken Kaufman and David Allen Sibley. People who are in your local birding community and have been doing it for some time can be of great help with identification, field marks, and habitat. Getting to know the other birders in your area can greatly help in your birding journey.