Managed WebHosting or Shared Web Hosting, I am confused.

Well if its a new wordpress site/blog with 0 per day visits, you may select any (managed wp would be costlier to start with in comparison with Shared).

My recommendation would be Shared hosting to start with.

Get a high bandwidth, generous inode limit[1] shared host to start with, once you anticipate having more than ~30k daily visitors, you may switch to managed wp hosting.