You should hire an expert to help you with your funnel or at least get a book on selling. A funnel is going to be specific to your business, and you are going to have to test to see what works. Look up the term "split testing".

Not every funnel works for every business. What works in one field fails in another. That's why you must test.

I could go into depth on each element of a funnel, but I think you need to get some basic learning done on sales funnels and split testing before we go into that level of detail.