Question: I have to talk to a software developer but I don’t know how..How do I start

So, I need to engage a software developer to develop a user interface where the user inputs an address and it will give the user a choice of stats on the entire building – or – lists all the units -or- custom request. In media, the process layout is called a storyboard. It walks you through each step to show how the story proceeds but what is it called in programming terms. I want to put together a step by step start to finish chart so that the programmer understands the process for the end user. Thank you in advance for this help.