The suspended app is the free builder that is building your docker image. If you don’t want this app at all, you can fly apps destroy BUILDER_APP_NAME and then when you deploy be sure to use --local-only to build the Docker image using your local docker daemon, i.e. fly deploy --local-only.
This is because you don’t have any Machines in this app yet. How did you create this app? Have you tried to fly deploy it yet?
If you go to the dashboard and click on your app, you should see a section labelled Hostname, underneath which you’ll find a URL of the form https://my-app.fly.dev. To visit your endpoint, go to https://my-app.fly.dev/hello in a browser.