Hi @roevisual, welcome to the Community. I'm happy to help you out and point you in the right direction for resources as well.
To start, it sounds like you're new to Expensify, so I'd highly recommend the Admin Training Webinar, which you can sign up for here. If you'd rather not wait to attend the webinar, we also have a recording of a recent one here.
Now, onto your questions and that additional help I promised.
How to be a company structure?
How to add more users?
How to set up a manager to approve?
I hope this helps!