How do I structure this?

Hi all,

Any help welcome. I'm completely new to this!

I'm hoping to build a three page form...

The first page will ask people to input a membership number. Which page they go to next depends on this membership number and an attribute I assign to that. So, I upload a CSV with membership numbers and attribute these with either a Yes Or a No in a second column. If they're a yes, they go direct to page three. If they're a no, they go to page two and then page three.

Hope that makes sense - any advice on how to make this work welcome!