Is your iPad recognized by an iTunes enabled computer when you connect it? If it is, it means the the iPad is working but not displaying an image on the screen. You could try to shine a bright flashlight on the screen to see if there is a dim image. If this is the case, then you either have a damaged screen or a damaged backlight circuit on the logic board.
If the iPad is not recognized by iTunes, then you have a logic board issue.
If you believe the screen is at cause, you find one here. As for guides, there are only partially completed guides for now. The problem with the iPad Pro series is that parts are very expensive and that makes troubleshooting it yourself not worthwhile. I would take it to a reputable shop, preferably one that has parts in stock for this model. They will be able to isolate the issue properly.