It depends on your theme …
Please give a link to website, or list your theme’s name .
first of all, you are using wordpress.com (and not inepenent wordpress.org) so you might want to ask there, for there are several things that you could not do with your template if you are a free user there …
Second, your comments show pretty well when you click the post itself .. do you want ALL the comments to show on the homepage ? this is higely not reccomanded , for the page can become very long .
If you still want to do that , just put <?php wp_list_comments('arguments'); ?>
Thanks where would I put that piece of code in?
EDIT: Sorry for double post
Well… read a bit HERE then HERE
and then HERE