So I just created my first build and installed windows... however I'm using a powerline for wifi and it says I need drivers. How can I get them if I can't use the internet... plus how do I know if any other components need driver updates ?
Unless it came with a disk and your pc has a disk drive you will need to download the drivers from another pc and move them to your build with a flash drive or other external storage device.
Your description is kind of confusing. Your PC is either connected over WiFi, or wired Ethernet.
PowerLine adapters do not need drivers - think if them as a very long Ethernet cable.