When you enable the VNC connection on a Mac, it will not let you login directly to the current user, but rather it will present you with a login screen after you've authenticated with VNC. This is convenient when you want to login to another account remotely, but not so much if you are trying to assist the current user (this is especially annoying for IT technicians, accessing the computer remotely and not knowing the user password)
There are various ways to restart and shut down your mac. The obvious one is through the Apple menu (there's very little magic about that), but the one that is more useful is using a command line. Because MacOS is a derivative of Unix, it has many tools hidden from an average user. To restart the system using a command line, open a terminal and run the following:
Q. Hello IT Support, I know there's a feature in BIOS for PCs to be turned on after a power outage. Is there such a function in a Mac?
A. Yes, this is a useful feature to have for remote computer access. If you login with an account that has administrative privileges, you should be able to do that. Go to: