Is this app going to be used by just a single store or is this app going to be in the Shopify App marketplace? If it is going to be in a single store, then I would recommend looking at private apps instead of a Shopify App. https://help.shopify.com/en/manual/apps/private-apps
@Shulebags , Shopify has also launched something called as Custom Apps that may be helpful if your scenario is to be able to share the same app to multiple stores. Here is the link for it https://www.shopify.com/partners/blog/shopify-public-apps
You can create a development store and try installing there, but is your authentication to install the app setup properly. It's not possible help out without looking at any code or examples.