New coder - need help with oauth



Only been coding for a few months and I’ve been trying to get into APIs. Well, most that use oauth have been a bit tough for me to wrap my head around. I’ve read the API dev. documentation about oauth and am not sure of…
A) which method of authentication I need
B) which keys get sent to which endpoint
C) parameter names to be sent in the headers

C is my biggest issue. I have various keys from my application but am not sure how to reference them. If it helps, I’m currently trying to understand this in powershell(most xp) while I study javascript. If there’s anybody willing to help, I would be most appreciative!

I’ve found others that have made modules for this, but I prefer to understand what is going on in the background before I start using someone else’s tools.