you asked for:
every category post displaying date,admin
any date and admin showing in the archive pages?
the date and admin might still show in other places such as the front page or single posts;
for the front page posts, edit index.php;
for single posts, edit single.php;
in both templates, find:
<div class="postdate"><img src="<?php bloginfo('template_url'); ?>/images/date.png" /> <?php the_time('F jS, Y') ?> <img src="<?php bloginfo('template_url'); ?>/images/user.png" /> <?php the_author() ?> <?php if (current_user_can('edit_post', $post->ID)) { ?> <img src="<?php bloginfo('template_url'); ?>/images/edit.png" /> <?php edit_post_link('Edit', '', ''); } ?></div>
delete exactly this section from the above:
<img src="<?php bloginfo('template_url'); ?>/images/date.png" /> <?php the_time('F jS, Y') ?> <img src="<?php bloginfo('template_url'); ?>/images/user.png" /> <?php the_author() ?>