Google and their YouTube product must be the direct cause of about 99% of all Mac problems. Don't go there.
Follow these instructions, including all the links within it: If your Mac doesn't turn on - Apple Support. In other words Step 3 will take you to if your Mac starts up to a blank screen. Follow the links within it, etc.
They all finish with "If you still need help, please contact Apple Support." Apple will tell you that Mac is no longer eligible for service, but they'll be happy to sell you a new one. Google already got their money from you.