Libreoffice Base

I am in the process of designing a database of online entry and payment database for a sporting event. I have looked through Jack Wallen's tutorial, very helpful.
What I want to do is have 4/5 initial questions(filters) that narrow down the specific competitions that any given applicant may enter.
They then fill their personal details, hit a pay (Paypal/etc) button and only once payment received would their details populate the master database.

Any help out there on this one?