I am looking for a tool/framework, that will have predefined components that will allow me to build website efficiently. Please recommend tools for beginners. I am expecting average db size, preferably MySQL, Website would be chat-blog like application, with functionality to crate topics/questions, and interact with it: like write comments or answers.
Have you looked at Drupal? We even have a site for Drupal questions.
It is very widely used, mature, stable, well documented and has lots of support.
You can build a website from scratch, or, as a beginner, choose an existing theme / template.
It has thousands of plug-ins (onown as modules), like shopping carts, multi-language support, etc, so I would be very surprised if it did not have one for your blog/chat functionality (I seem to recall doing something similar, but that was 10 years ago, so my memory is hazy).
As of December 2019 the Drupal website lists more than 44,000 free modules. Core modules include Blogs, books, comments, forums, and polls.
Take a look at the Drupal chat plugin.
DrupalChat allows visitors of your Drupal site to chat with each other privately or together in a public chatroom. This module enables sites to provide online support for their products/services, and thereby increases user engagement. Also, it is useful for social networking sites, forums, blogs, etc. It logs the user conversations so that they can be later viewed in message inbox. You can try it out live here.