Juno is one of internet services providers in United States. Previously Juno would give you email address if you registered to their service and you could use it by using specific email client. But today they offer free email address even we can sign in through web browser without install their email client.
To sign up at Juno email, you can go to Juno webmail and click [Create a New Email Address for Free] and it will open new tab for you and then click [Get Started]. Next you can fill the form with right data and then click [Submit & Continue] and if it success you will have mail address at Juno email. To sign in just go again to Juno webmail and fill that form appropriate with your address and password and click [Sign]. Explore the email to find some feature on it.
I hope after you know Juno email will make you comfort with your internet and computer.