You can opt to allow or disallow comments for your posts. You can either set them individually or for your entire blog.
Setting for individual posts:
Before PUBLISHING your post, click on OPTION on the right column of your post.
From here, you can either ALLOW or DON'T ALLOW comments.
On your DASHBOARD, click SETTINGS, POSTS and COMMENTS and then choose if you want commenting OFF your blog or which level of control you have over comments.