Pro Sites Checkout Page

All I want to do is accept payment through PayPal and stripe using the pro-sites plugin.

I will register the accounts and send them their password etc. I have already done a trial run using my PayPal sandbox account and it seemed to work. There are only two problems:
The pro-sites checkout page does not display properly - If a new user goes to the page (somehow who does NOT already have an account) the payment options are constantly hidden.
The second problem is that I don't really know how to set pro-sites up properly because there is no documentation.
Sure there is the usage section - but this only has one sentence explaining payments