How to create a custom block with fillable params

Hi guys, first of all excellent work! I tried following the tutorial but I am unable to understand how to add a custom block, to which after selecting it the user can fill in parameters (name and title for example) from the menu on the right. I read about blocks, components and traits but I fail to understand how to write a new block (or component) myself. Would someone be so kind to write me a very simple example? e.g. drag and drop a block that adds a <p>Hello world!</p> tag. After you click on it the user should be able to add classes, a title and fill in a value for a "data-name=''" prope...