Can be largely simplified by using Tags. Tags can be applied at the subscription level, resource group level and resource level. Tags are metadata on resources. An example is the name-value pair CostCenter. Other examples are Environment and Classification (public, sensitive, secure).
You can use up to 50 tags per resource. Tags cannot be inherited, but you can define policies to automatically add tags to reources when they exist on the resource group. See: https://docs.microsoft.com/en-us/azure/governance/policy/tutorials/govern-tags.
Related to naming conventions: Microsoft Docs.
In the Azure Portal go to your subscription or resource group and start Cost Management. Here you can for instance filter on Tags. You can also define a Budget and assign it to a subscription or resource group.