2. If you would like a follow button to appear on the bottom right hand corner of your site for those who do not have WordPress.com accounts see here >
http://en.blog.wordpress.com/2011/09/21/more-traffic-for-your-blog-with-the-follow-button/

3. You can set up a customized contact form http://en.support.wordpress.com/contact-form/ on a static page http://en.support.wordpress.com/pages/ or in a text widget http://en.support.wordpress.com/widgets/text-widget/ and above that form you can ask those who wish to have their email address "captured" to use it.

Note: Your site stats page displays how many followers you have, who your followers are, as well as how many people are subscribed to post comments on your site.

Dashboard > Site stats > Total, 'Followers' , Shares
http://en.support.wordpress.com/stats/#totals-followers-shares

Click "blog" and when that page opens click "email followers"
http://wordpress.com/#!/my-stats/?blog_subscribers&type=email

watched videos on you tube but nothing is helping everyone has the plug in option

There is no FTP access to free hosted WordPress.COM blogs and we cannot install plugins. Those found on the internet are for WordPress.ORG installs which run on different software.
http://en.support.wordpress.com/ftp-access/
http://en.support.wordpress.com/plugins/

There is no upgrade that you can purchase from WordPress.com that provides FTP access and the ability to install plugins in a free hosted WordPress.com blog. See > http://support.wordpress.com/com-vs-org/