Multisite Initial Learning and Practice

Hi Heroes,

I am very new to multisite and basic knowledge in Wordpress. Not technical at all and no coding knowledge. However, over a period of time i learned little bit of wordpress and can do little bit of it.

Now i want to learn Multisite creation and i don't know where to start the learning. sometimes, i install pro member, some time upfront and many more. clue less now. Anybody guide me where to start and learn step by step.

My high level requirement is to setup a multisite network for my subdistributors.
I want a parent site (lead page) with pricing slabs, features of site and about us and few more pages. Now on this page my subdistributors can come and choose monthly or yearly plan and can choose a fixed theme for their site (this theme will contain home page, products already uploaded, contact page and 1 or 2 more pages). Please note that products will be there with 3-4 categories and they can change the category and product image if they want in their own sites but not in my parent backend database. They might can change content and any image from theme template which they choose. And i don't need cart, payment or shipping on sub distributors site. on Buy button, it will take them third party site to purchase like affiliates.

So how do I create my parent site with front end for my subdistributors (basic and pro feature payment mode) with required backend change management for them. And how I put 1-2 Themes for them to select for their subsites.
Individual domain mapping, autoresponder for subsites etc. I will learn later but I want first start to learn.
Thanks to all.

Regards,
Arun