Very basic theme you have there. It's uses
index.php for nearly everything. (at least the version of it that I found online) An easy way to accomplish want you want is to create a new template file called
page.php Make it an exact copy of
index.php WordPress will now use that template file to display pages.
To stop the date from appearing delete this ...
<h3><?php the_time('F jS, Y') ?></h3>
With respect to comments you can close comments for those pages in the Edit Page screen.
If you want to go one further, open page.php and delete the call to the comments php file ...
<?php comments_template(); ?>
You can also delete the comment link ...
<?php comments_popup_link('No Comments »', '1 Comment »', '% Comments »', 'commentslink'); ?>
If you're interested here is some reading on the WordPress Template Hierarchy. This link explains what template files WordPress uses in a given situation.