Cannot find subscribers/followers

I purchased this from someone. I have no experience running a site. This came with Genesis the theme is décor child theme. When I purchased this the women told me she had about 247 subscribers. I cannot find them. I have not decided on what email client I will use, I want to do a newsletter. I have looked on dashboard but all I can find is Home-Updates-Akismet Stats-Most shared posts-WassUp keywords-WassUp stats…I have checked stats and still cannot find subscribers or followers. When I click users all I find is my name. The previous owner was using aweber and needed to remove the plugin. Is there a plugin that I need to install to be able to see the subscriber list. Thank you.