The Kodi System

Kodi is an interface program that gives you access to audio, video or still image files either locally (from your own device) or from the internet by using plug-in scripts called "Add-ons". As an example, you can use Kodi on your computer to view digital photos, watch videos you took of your summer vacation, play your MP3's or watch free movies from the Crackle website.
Take Kodi a step further by installing third party Add-ons and gain access to a huge library of TV shows and Movies.
Kodi is a free program and most Add-ons provide free content. There are some subscription based sources as well if that interests you but it all depends on what kind of content you are looking for.
Many people have Kodi on an Android Box or Amazon Fire stick and plug it into their HD TV's. If your TV is a Smart TV with an Android operating system, you can install Kodi directly into your TV menu.
When I tried Kodi for the first time, I install it onto a desktop computer. When I got comfortable with it, I plugged the computer into my 55" TV and operated it with a cordless mouse. Shortly after that, I replaced the computer with an Android TV Box from Amazon, then canceled my TV cable service which cost me around $100 per month. My cable service gave me 500 channels of crap I didn't want to watch. Kodi gave me only the stuff I wanted, commercial free, on demand.

Read all about Kodi and download the most recent version of their software here: https://kodi.tv
You will also find it as an App on the Google Playstore.

Add-ons

As mentioned above, Add-ons bring you the content that really powers Kodi. Without Add-ons, Kodi is a simple utility program that doesn't do anything spectacular. With Add-ons, you can build a system more powerful than any streaming service. You can actually cut your TV cable and save hundreds of dollars.
To find these amazing Add-ons, you can search YouTube or check out this website: https://kodiapps.com
Personally, I find YouTubers give me better information about what's hot and what's not. The only issue with YouTube is that a lot of older videos are no longer relevant as the world of Kodi is constantly changing. Always try to find the most recent videos.
Please note, these third party Add-ons are created by Developers for free as a hobby. If a Developer decides to stop support of their Add-on, it dies a slow torturous death. This is why you need to be diligent and make sure you keep your Kodi updated with the most current and updated Add-ons. I personally have several Add-ons in my Kodi in case one dies I have others to fall back on. You may also get different search results depending on the Add-on. One may find lots of links to newer videos while another gives you better results to older videos. It's the old "don't put all your eggs in one basket" type of setup.
If your Kodi completely stops working, then it's on you to be proactive and fix it.
A great support Forum which keeps you updated on problems with Add-ons is on the following website:
https://www.reddit.com/r/Addons4Kodi/
Of course we will also try and keep you updated on the Streaming AVE forums as well, but the above mentioned Forum is filled with Developers and coders who are on top of issues 24/7.

Skins

It's probably obvious to most what a "Skin" is, but simply put it's the overall look of Kodi. That includes menu design and feature controls.
Out of the box, Kodi has the "Estuary" Skin. It's the Default look of Kodi, but you can change it any time to something that you believe looks better. It's a personal choice and different people like different skins.
I prefer a skin that focuses more on functionality than esthetics which is how I chose the skin for my build,
It's not something you have to think about until you get bored one day and want to play around with it. The default skin is a good one.
To load skins, you simply go to System -> Interface --> Skin. Click the "Get More" button for a full list of available skins.

Builds

As you become familiar with Kodi you will see a lot about "Builds".
Builds are simply a collection of current Add-ons installed into an alternative Skin and offered to the public for free.
Anyone can create a "Build". As soon as you install Kodi and some video add-ons to view content, you have created your own simple build.
If you change the skin of Kodi, you have a more enhanced build. If you customize the skin you have an extended build which is what Build Developers are doing.
If you create your own skin, you are a coder and far beyond anything I, or most Build Developers. could ever do.
For my first build, I customized the Xonfluence Skin by changing code files and modifying some images. After the skin was modified I simply plugged in freely available Add-ons. Since I already had a server, I was able to create a repository to share my builds.
The advantage of using someone else's "Build" is that it allows you to install Kodi and use it right away without spending a LOT of time trying to figure out what works the best. You get the benefit of someone else's time and research into what works and what doesn't. Finding a good add-on that provides you with what you want can be like finding a specific ear of corn in a corn field.
Best of all, like almost everything else with Kodi, Builds are FREE!
You can see a current list of "some" Top Kodi Builds here: https://www.firesticktricks.com/best-kodi-builds.html
I'd also suggest searching YouTube as you may find less known builds that are amazing.

Real Debrid and VPN's

Read Debrid is a paid service, but for approximately $3 per month is more than worth it when using Kodi. Nothing is more annoying than your show freezing (buffering) while you are watching it. You may have the fastest internet, but that doesn't help when you are trying to stream from a slow and overloaded server.
The advantage of Real Debrid is that it brings you IMPROVED sources for TV shows and Movies. You get more HD links, more reliable links, and less chance of buffering problems. If you want to save the $36 a year and stick with unstable links, then you can stay with that.
Real Debrid also works like a VPN service. If your Internet Provider is monitoring you, they won't seeing you connecting to servers of "questionably obtained content", they will only see you connecting to Real Debrid. What you are getting from Real Debrid, only you and Real Debrid knows for sure.
If you don't have Real Debrid and can't find a good HD version of a movie, don't complain. RD is the cheapest service you can buy.
Real Debrid is paired to your Video Add-ons in most cases via your ResolverURL and URLResolver Dependency Add-ons.
To can sign up to Real Debrid click here: http://real-debrid.com

As for VPN's themselves, I personally don't use one. If you are downloading pirated content directly from Pirate sites, then it might be a good idea to get a VPN in case someone is monitoring your activity.
VPN's are also useful if you have issues with Regional Content. As an example, someone in Canada may be blocked from seeing a video originating from the United States on a specific website. However, a VPN can route that person to an IP in the United States so it appears like that person is actually within the U.S. allowing the content to be viewed. I don't have issues with that myself so I really have no use for a VPN.
As a side note, Real Debrid can also be used to download content as well, (such as Torrent sites) keeping you anonymous just like how a VPN works.