I will recommend the steps below:
Go to the App Services section and locate your resource group ("learn-b17c4847-5cf0-43c2-942d-a0afdb4e36a3") and check if your web app named "BestBikeApp" exists within this resource group.
Confirm the exact name of the RG and app (You can copy to make sure) and deploy again:
az webapp deploy --src-path site.zip --resource-group <correct-resource-group-name> --name BestBikeApp
See: https://learn.microsoft.com/en-us/cli/azure/webapp/deployment?view=azure-cli-latest
You can mark it 'Accept Answer' and 'Upvote' if this helped you
Regards,
Abiola