To get to your networking controls, Click the Network Icon in the Taskbar, next to the time.

You can see and perform many tasks from here.

Disable Network Adapter
Click Change Adapter Options
Choose the adapter you wish to disable, and either Right-click and select Disable or select the adapter, and click the button on the Toolbar to Disable This Network Device.

Determine Link Speed

Select Network & Internet settings

Under the name of your network, click the Properties button.
Settings Window of Windows 10, showing Network Properties. an arrow is pointing at the bottom towards Network Band, which shows 5Ghz, and Link Speed, which shows 585Mbps.
Scroll down and look for Network Band, and Link Speed. Link speed will NOT be your internet speed, it is simply the maximum speed your link will allow.