Hi Rebecca, it looks like your git repository is in the src/pages folder of your gatsby site, rather than the full gatsby folder. Netlify uses the build script in the package.json file to create the site so the repo needs to include it to recognize your project as a gatsby site.
Try creating the repo in the parent folder of your src folder, which should be named whatever you named it when you ran “gatsby new” (it looks like in the above tutorial they named it “gatsby-site” in step 5).
Once you push the repo to github you should see the src folder as well as a few configuration files like package.json on the top level. When you see this you should be ready to connect it to Netlify.
Hope that helps - let me know if it doesn’t work for you.