Thank you for your question!
There's no need to add review rich snippets manually. We've integrated structured data in all our themes. However, please note that Google doesn't always create a rich snippet of your page. There are no guarantees. This is because search features depend on many factors, including the search device type, location, and whether Google thinks the feature would provide the best search experience for the user.
This blocks is available on Da vinci 1 theme, and right now i'm using Davinci 2.0 dropship theme, i want to use that blocks into my website. Can you please tell me the code ? Because I have no coding knowledge??
You need to have profound programming knowledge to make these changes. These are beyond of simple CSS code you can add to your Customization. You might want to ask your developer to help you with these changes.