How do you play Second Life

Second Life is a free platform. In order to play you need to download the client application from SecondLife.com, and your computer must meet the system requirements listed on SecondLife.com
Register secondlife and join. Follow the instructions there, which will tell you how to download and install the client program. You then sign into the world by running the client and entering your username and password.
You play secondlife on the download. You DO have to download it to play it, it is virus free and is really great!
Once it is downloaded you can log in. You walk with the arrow keys and click around like normal, right clicking is important in this game too. Have fun!