Typo3 TypoScript, display plugin - typo3

Question

I try to create a simple hello world plugin for Typo3. I have the code and all is fine, plugin is installed and i added it to the page as a content. But the controller is never called and templates are never rendered.
I followed this tutorial https://docs.typo3.org/typo3cms/ExtbaseFluidBook/4-FirstExtension/Index.html
and even installed their extension from github. No effects, Typo3 wont render anything. Pls, send help.
EDIT
I just installed a "Preconfigured Distribution" from extensions manager and suddenly all plugins work. It will do for now, as long as I see my extension working.

Answer 1

Probably you just forgot to include the static TypoScript in the root-template for you page.
On the way to create manually extensions there can be many 'stones' which make it difficult to make it right or to find a fault, but the hint above is the first thing to verify / configure.
Usually for creating extensions another extension is used, it's called Extensions Builder and can be found here. This extension creates a lot of basic code and simplifies the first steps very much.

Answer 2

You have to make your TypoScript selectable in BE with this line in you ext_tables.php
\TYPO3\CMS\Core\Utility\ExtensionManagementUtility::addStaticFile('yourextkey', 'Configuration/TypoScript', 'Title of your Extension');
After adding this line, clear the System-Cache (the "red one") and go to the Template-module in Backend.
While in template-module, select your rootpage in the pagetree. On the top you should see a dropdown menu where you have to select Info/Modify.
In the Info/Modify-Page, select Edit the whole template record and after this, swith to the tab Includes.
There you should see Selected Items and Available Items. Your Extension should be in the available items, where you select it and press the save button.
If you have done everything else correct, now your TypoScript setup should be loaded and your plugin should output something.