Hi JadenK
Yes, you can get submitted sales orders from D365 Sales to Finance and Operations, BE (D365 FOBE further on).
Once you prepare sales order in D365 Sales, you can click a button names Submit Order which makes such sales order available in D365 FOBE.

In D365 FOBE search for Dynamics 365 Sales Orders and there you can click button Create in Dynamics NAV button

Once you post such order you can open posted sales invoice and click Create Invoice in Dynamics 365 Sale to send invoice back to Sales.

This can also be automated:
- Sales orders can automatically get created when they are submitted by setting Automatically Create Sales Order to Yes in Connection Setup page

- Posted sales invoices are can be automatically synched when POSTEDSALESINV-INV job is run.
Unfortunately mappings can't be changed at this time in D365 FOBE.
Please keep an eye on our roadmap site for upcoming improvements in this area.