I assume you mean the “Default” theme? Ye olde’ big blue box?
If you look in default theme’s sidebar.php, you’ll see a block like this:
<li><h2>Meta</h2>
<ul>
<?php wp_register(); ?>
<li><?php wp_loginout(); ?></li>
<li><a href="https://validator.w3.org/check/referer" title="This page validates as XHTML 1.0 Transitional">Valid <abbr title="eXtensible HyperText Markup Language">XHTML</abbr></a></li>
<li><a href="https://gmpg.org/xfn/"><abbr title="XHTML Friends Network">XFN</abbr></a></li>
<li><a href="https://www.ads-software.com/" title="Powered by WordPress, state-of-the-art semantic personal publishing platform.">WordPress</a></li>
<?php wp_meta(); ?>
</ul>
</li>
Remove some or all of what you don’t want. Curious about what wp_meta() does? Have a look at the template_tags documentation.