It can't connect to Wi-Fi at all. I can't even see a Wi-Fi option. How can I fix this?
Most probably your WiFi drivers are outdated. Because you are using apple provided drivers, you should have looked up if windows 10 is already supported. Apples homepage shows that:
Boot Camp 5.1 supports 64-bit, non-Enterprise versions of Windows 7, Windows 8.0, and Windows 8.1. This version of Boot Camp doesn't support Windows XP, Windows Vista, or any 32-bit version of Windows.
they don't mention windows 10, they don't say it's supported. if you do have outdated drivers, you could (and you should have) tried the latest boot camp drivers. Nobody from us can help you here. You have to wait until apple releases the new bootcamp drivers.