After you will reached this page -
There are the option - Learn more, Send chips to mafia, Try for VIP access.
If you have chips than you can try for VIP access and if you are lucky than you get the access or you have to wait 22hrs for next try.
You can send chips to mafia to get more chips that your increase your % to access.
And if you click learn more than you have three option to start your journey to Las Vegas.