Go to the web site and click on browse. Here, you can find girls two ways.
The first way is to simply look at the list of girls. You may want to change the settings to show ALL girls, and only those that fit your criteria (blonde, brunette, shaved, European [nearly all are that], etc. and many things or special outfits). Go to the very bottom of the page and check what you want to see. On the bottom right, you need to click Okay. On the bottom left you do not need to do so.
Also on that page, you will see 'ALL GIRLS' on the top right. Scroll through every single card on the site. Just click a name. Clickin the name will take you to the card immediately.
When you get to the page of a girl you like. Just click the "get her for two tickets" (this will say just one ticket for those that have 'special offer') spot, and then click OK if you are sure. Once bought the girl is yours forever.