There are multiple means to access your email:
To access your email via your web browser, kindly point your browser to your domain slash webmail
Example: if your domain were example.com you need to visit example.com/webmail
To access your email using an email software like Outlook or Thunderbird, kindly enter the following settings into your email software. Assuming your domain was example.com, the settings should look like these:
IMAP3 Host Address: mail.example.com
SMTP Host Address: mail.example.com
Username: The FULL email address that you are picking up from (e.g. firstname.lastname@example.org).
Password: As specified in your web hosting control panel