Initial Sandbox Setup

My company is purchasing a second domo instance to implement a dev and prod environment. We want to keep our current instance as the dev instance (sandbox) and make the new instance prod. What are the best practices to prepare and get started for this transition? I think our team is comfortable with the idea of promoting dataflows and content, but we have question around:

• How to migrate our connectors to the new prod instance?
• How to then ensure virtualized data from prod is available within sandbox?
• What's the best way to set up user accounts in prod? (Create all new users with view only access in prod, or migrate from current instance.)

In general any insights, tips, guidelines, or KB articles on the initial setup of Sandbox/Prod instances would be highly appreciated.

Thanks, Sarah