Drupal 8 multi fields in one fields
If you prefer another approach, a little more clean and following the Drupal structure, you can use Inline Entity Form to do that.

I don't like Paragraphs and Field Collection for just one reason. They don't follow the way that Drupal storages data in DB. If you open your database and search for the tables that this modules create, you will be able to see some strange patterns.

https://www.drupal.org/project/inline_entity_form