Yes, Nokia 8.1 does have the USB Type-C port.
Yes, Nokia 8.1 does have the 3.5 mm headphone jack. It also has Bluetooth A2DP support.
No. Nokia 8.1 is not a water-resistant phone.
In the official packaging of Nokia 8.1 - you will get your Nokia 8.1, USB Type C cable, Power adapter, Headset, Quick start guide & SIM door key.