After receiving your VPS login details, the first thing you'll want to do is log in to the VPS. If you have never used a command line before, you may want to read our Knowledgebase article "How to Connect to Your VPS with sFTP."
An SSH (Secure Shell) client is required to connect to your VPS. Linux and Mac OS X users can benefit from pre-installed terminals (Terminal, found in /Applications/Utilities, or Konsole in some Linux distributions). Windows users should download a program called PuTTY, found here: http://www.chiark.greenend.org.uk/~sgtatham/putty/download.html
To connect to your VPS, enter the following in the terminal (inserting your server's IP address), press enter, and type your root password when prompted:
# ssh email@example.com