Greetings prospective front end developer! I've put together a quick exercise as a basic test for some of the skills we use everyday. This is a Fiddle that fetches my starred GitHub repos and displays them. This is done in a straightforward way of creating the elements needed and adding them into the DOM. I've set the Javascript window to use Babel and the styles are in SCSS.
Recreate the Fiddle using React! Have a poke around and see how the elements are structured and styled. Use any methods of styling and layout you want. Recently I've been enjoying Styled Components if you want to take a crack at that.