Online invitation help

I am wanting to send my save the date via email, and then will mail my actual invitations out later, and im just a little confused on the online invitation option. Is there a way to send a email to just 1 person? And how to do you know who you are sending the emails too? When I click on one person and click send online invite it takes me to the screen to send the email but doesn't say who its going too, im nervous it might send it to everyone on the guest list and am just a little confused.