The sequence of the creation of a db, a user, the according permission and all that sort of things!?

[Joe]

You’re right, we have already had this conversation. So why are you still asking what order to create the user and database?

Which steps to take while setting up a new db on Webmin

The order doesn’t matter. You can create a user or a database first. Then permissions last. Virtualmin handles all this automatically for domains managed by it (at least for the general case, you can still do fine-grained user permissions and stuff in the Webmin MySQL/Mariadb module).