You may have started to notice there are a few different colors and shapes to the codeblocks.
Events are a lighter square shape. The darker square shaped codeblocks can go inside of events, and often have rounded pill slots, which are for values and variables. Notice these values and variables are color coded to signify their type. There are also rounded codeblocks, which get or manipulate values. These will fit into the pill slots too.
VARIABLES precedes this tutorial