There are 2 ways
1) Turn off Globally. Go to Settings/Discussion and then turn off comments for new articles
2) Turn off per page: Go to the bottom of your page in the edit screen of each page. At the bottom you will a box labelled discussion with an allow comments checkbox. Just turn this off. If you can’t see this option, then you first need to click on screen options (top right) and tick discussion. Now when you scroll to the bottom of the page you will see the option to turn off comments.
Let me know if that does the trick,