Do I need to register copyright in my work? What are the benefits?

No.

Copyright subsists in an original work without obtaining any registration. Moreover, as soon as you post something publicly (publish your content), your copyright in the content gets further established. Also, in view of some treaties entered into by the countries, copyrightable work created in one country is protected in most other countries.

However, copyright registration can be helpful in certain circumstances, such as in case of court proceedings where copyright is challenged or in cases of infringement of copyright where copyright registration could help establish ownership in work.