How to: Build a Workflow

Hy, I am running NC-aio v12.8.0 Hub 26 and I try to rebuild a workflow to approve something.

I create some tags (approved, needs-approval and rejected) for the process. I know that the Flow app is in the core inside so i dont need to activate it. But I activate the workflowengine app.

Now, I don’t know.. how to build the workflow for this steps:

=> Upload document
=> Document gets the tag needs approval
=> Approve users geht a notification and approved the document with setting the tag or rejected it
=> After Approved or Rejected the Creator of the document, gets a notficaion on that.

Can someone help me please?

Thanks.