[What is the most recomended viewer?]

I was wondering which viewer is best recomended for an old user like myself. I want to rejoin Second Life with my old account and character, but I saw that the "Viewer 2" thing is much different from the first original viewer from many years ago. Is there a viewer that is similar to the first?

[Please help!]

How do I update my account to where I live now? My account is 3 years old and I moved to a new place in that time. How do I update it so I can age verify?