In new WordPress comments are On by default but many people who want static websites generally do not need Comments in there posts/pages.WordPress provides some inbuilt functions for activating/deactivating comments in your site.
1. Activating/Deactivate comments through Pages/Posts:
This includes 2 processes.
a) Enable/Disable Comments:
For enabling/disabling comments you need to go to:
Dashboard > Pages/Posts > Edit the Page/Post where you don’t want to see comments.
On the top right of the screen you can see Screen Options. Expand that and look for the Discussion box there. Check that if you want to enable comments in that page/post or uncheck that if you want to disable comment in that page/post.
Then on the bottom of page, you can see the Discussion box like the below figure. You can check or uncheck the Allow Comments there to enable or disable comments.
b) Bulk Editing Comments:
If you want to adjust the comments then this is considered to be the best method. Here in this method you need to go to:
1. Dashboard > Pages/Posts.
2. You can now see the list of Pages/Posts in your screen. Select the Pages/Posts you want to adjust the comments by checking the check box at the left of each post (However if you want all pages/posts to change then you can tick the check box at the left of title at the top).
3. Select Edit from the Bulk Actions Drop down and Click Apply.
Then you can see a new screen appearing in your Screen. There in between the 5 drop downs you see you can find one Comments drop down is there. You need to select Allow/Do Not allow as per your requirement there and save the changes.
2. Activating/Deactivate comments through Setting:
You can deactivate comment by going to Settings > Discussion > Default article settings > uncheck Allow people to post comments on new articles > Save the Changes.
In this Process you can deactivate comments only of those Posts/Pages which are published after you have done the change there.
Hope this article helps. Thank you.