@davidhaven1246 Have you checked out the documentation on using the basic registration form? Will enabling the Self-service registration for the application what you are after? If not, a little more detail on your flow and how you have implemented may help.
This post may help provide some clarity as well for an invitation flow. Keep in mind, this flow utilizes some paid features of FusionAuth, but you may be able to figure out some work arounds with the community edition.
This post talks about passing some parameters in a link that may help as well.