New Transfer - Basic Question on How JR Functions

I am a new transfer and have been clicking around in my new JR. I am a Ning importer and have used WP for many years--and am trying to wrap my brain around the new lingo and layout and how to set things up.

I have looked at the tutorials, which I am sure will be handy. But as far as understanding layout and basic changes, would you suggest this video as the best place to begin?
https://www.udemy.com/start-your-own-online-community/?dtcode=q3gqiZA2EEXh

Also, what are my options for being able to add html to places like the homepage. In wordpress, for example, I would put in a text box widget where I want it. I am trying to figure out how/if I could do this in JR.

If a module is "sort of" a widget, is there a module that could include html only? I looked, and didn't find it, but it was just a stab in the dark. I don't even know if I am looking for the right thing.

I am using the Ningja Template and made a clone as well.

Thanks for pointing me in the right direction.
updated by @restmin: 05/06/15 09:22:26PM

Absolutely. I made that course and its a great place to get started to understand Jamroom.

Let me know if there is anything in the course you get stuck on or want explained further.

If watching videos isn't your thing, then the docs from here:
https://www.jamroom.net/the-jamroom-network/documentation/contents

With special attention paid to these ones:

* "Concepts the Admin user needs to know"
* "How to install a module"
* "The Jamroom quota system"
and perhaps the Glossary
--edit--
With regard to 'widgets', the system that deals with that is the Site Builder system. It will allow you to add different widgets including code to your pages. Site Builder has its own project page here:
https://www.jamroom.net/site-builder/

and forum here:
https://www.jamroom.net/the-jamroom-network/forum/site-builder

updated by @michael: 03/30/15 11:32:20PM