I am no expert, but from what I understand, Neo-Druidry is the modern practice of the Druidical belief system. It is not the same as what Druidry was a few hundred years ago, but pretty similar. It isn't so much a religion as a reverence for nature and harmony. Back in the older days, the druids were healers, advisors, and bards who recounted history through song and poem. Since very little is known about the older druids due to extremely little literary history. The modern day druids are referred to as Neo-Druids, referring to the fact that they are reviving an old belief system based on the idea of it.
It would be near impossible to be just like a druid from the old days, although I am sure there are probably small groups out there who are following the same practices as back then with teachings being passed through oral history.