If you don't already have an email client program on your computer, or you'd like a better one, you can download Mozilla Thunderbird for free: download Thunderbird
Once it is downloaded, run the installer. The first time Thunderbird runs it will start with the New Account wizard.
If you don't get the New Account wizard, you can start it in either Edit menu, or Tools menu. Find Account settings / (in Account Actions at the bottom) Add Mail Account
Enter your name, email address and password into the setup wizard, and press Continue. Unfortunately the wizard doesn't always guess correctly, and you may need to use the Manual Configuration button. Then use the general email settings page to answer its questions.