Single Page Design Portfolio using React and SCSS

What are your thoughts about the general structure of my SCSS files? Should I have separated more of the content on the page into React Components to help reduce the amount of code in the main App.js file? I wrote a few tests, I don't typically write tests, but are the tests I conducted in the App.test.js file good? I was going to add tests for clicking on the carousel buttons, but I was a little confused on how to approach that.

Any other feedback is appreciated as well.

Thank you.