Hello @mmdalire! Welcome to the community 
Netlify will build your site using the build commands you provide, then deploy the artifacts from the build using the directory that you indicate. Within that directory, Netlify is designed to serve index.html files by default. If you request a URL that doesn’t have an index.html page, that page is shown.
I took a quick peek at your netlify.toml file and don’t see any build-specific commands to run or build folders to deploy once the build is complete defined there. Those will need to be indicated either in your netlify.toml file, or via your site settings on app.netlify.com.
You can check out more troubleshooting steps in this post: [Support Guide] I’ve deployed my site but I still see "Page not found”, one of which is to try downloading the build results as indicated to see what was actually deployed. In your case, I’m skeptical to say that anything was even built in the first place, although I don’t know what your site settings are. Best of luck!