I'm new to web development and looking for a platform which can support a project I'm working on. The idea is to have a text available online which can be viewed by many users. Each user can access the text and add tags to parts of it (paragraphs, sentences, whatever..) and see other users' input.
Features I'm looking for:

Support for multiple users

Options for private/public listings

Extensive database for searching all user listings

What frameworks would be relevant for supporting this?

I don't have any web development experience, so essentially I'm looking for some pointers so I can focus on the right direction. Doesn't seem too complicated, so I'm hoping to save development time by using existing solutions.

Thanks in advance, Ronen