Dear @Leoj,
For bandwidth usage, you can see the following data:
WAN Information
Log in to the web page first. In the navigation tree on the left, choose System Info > WAN Information. In the pane on the right, you can view the WAN information such as the status of the WAN interface.

Eth Port Information
In the navigation tree on the left, choose System Info > Eth Port Information. In the pane on the right, you can view the Ethernet port information such as the speed.

WLAN Information
In the navigation tree on the left, choose System Info > WLAN Information. In the pane on the right, you can query the WLAN information such as the Wi-Fi port status.

For bandwidth limitation, you can set it under the QOS configuration menu:
In the navigation tree on the left, choose Advanced Configuration > Application > QoS Configuration. In the pane on the right, you can configure the QoS parameters, then click Apply.

Thank you!