Hi @scrim,
Welcome to the Auth0 Community!
You are definitely on the right track. User management can be done directly on the Auth0 Dashboard, or can be done via the Management API. The management API will require you to build your own UI, but provides more flexibility and ability to automate. This will need to be connected to a backend where the calls are actually being made, as it is more secure.
For users to add additional information to their profiles (user_metadata) you can make a call to the management API directly from your Angular app. SPAs are limited in scope due to their exposed nature. See more below:
In regards to storing user data, that can be done locally and by Auth0. You probably want to store a copy of user_id in a local database as users log in. Then you have a place to store more in depth user data like posts, blogs, etc.Typically the data stored in user_metadata or app_metadata should be related to authentication/authorization. Check out this best practices doc:
Let me know if this helps or if you have any further questions.
Best,
Dan