Plugin for Registering Members

I’m developing a website for a new political organization. I want to be able to register members, collect pertinent information they supply, keep it in a database and email them as needed.

I’m not a coder at all, so I need something easy to install and use. I saw a plugin called “Participants Database,” which got great reviews, but I could not figure out how to install in on my site.

Can anyone recommend a good plugin for me to use?

Thanks so much.

Greg Falk