Rock right to left to navigate backward, and left to right to navigate forward.
As soon as you log into Windows, the default setting will be the function keys. When you boot up Windows via Boot Camp, the Touch Bar will display the function keys F1 - F12 and an escape key.
If your computer doesn't have a dedicated number pad on the right side of the keyboard, you won't be able to turn on the Accessibility feature that allows you to move your mouse around with the number pad. Apple's built-in utility, Boot Camp, lets you install Windows onto your Mac using a partitioned drive. Make sure that your computer has a number pad.