Answer:
go to http://www.imvu.com and click start now. After entering your email address and age and other things, It should ask you to download IMVU onto your computer. After you do so, Verify your email address by signing into your email, go into your inbox and click on the new message from IMVU. It will then tell you to click on a box that says "click here to verify your account". Once you've clicked that, a new window will appear and state that you have verified your account.
If you would like to play IMVU, then go to the downloaded version and sign in from there. Once you've signed in, it should take you to the game.