there is website about unblocked games - who knows how can we make flash games? is it difficult? and what kind of education is nedeed?

The tool to make Flash games was a tool called Adobe Flash. Flash has been unpopular on the web for several years and is not generally used for new work. 

The tool has changed over the years and is now called Adobe Animate. It can make games targeting HTML5 canvases in addition to the older Flash-based games.

There is no good way to describe difficulty for using the tool. Difficulty is relative. If you have experience with tools that manipulate timelines and animation clips, if you have experience with graphics tools, it is not particularly difficult to use. If you have never seen the tools before it may take some effort to learn how they work. Millions of people have learned how to use it, and if you get stuck there are many online resources to help you.

This is not a Game Design question. Moving thread to a more appropriate forum.