The wiki how images are really good and make users stay a long time on the page.
This is one of their pictures. I also want to make pictures like this.
How to make pics like them?
These are made by artists with training. If you wish to learn this you will have to learn graphic design and illustration.
Get a graphic design course on Udemy and get started!
what tools these people use to make such images?
can you list me few Free and paid tools?
Designer mainly using Adobe Illustrator for draw images like this screenshot.