How do I integrate Membership plugin with my land page?

I have created a table landscape page with for membership options of my site, using the theme provided buttons (I simply added the membership URL for each type of subscription) however, when I click on them it does not work (it suppose to show the subscription form paypal button and after that the subscription form) I think it is a rookie mistake, could you please take a look on the page and see if you can share some wisdom on how to correctly integrate membership plugin with the theme. Thanks in advance.