Hello Sir,
I have read your provided requirements and fully understood that you need someone who can help you design schema for your application. First of all, I have gone through such processes and have developed small and large scale application from scratch including the database schema. I am basically a backend developer with experience in developing database structures of complex applications. Please feel free to discuss me anything or shoot your queries if you have.
Try me once, and I assue you will not get disappointed.
Thanks.