The Universe came from something - G-d’s thoughts. As for G-d, He just was, is and will always be. We CANNOT understand that or prove it scientifically, simply accepting that it is so is what is called for.
Well said, similar to this: Deut. 29:29: The secret things belong unto the LORD our God: but those things which are revealed belong unto us and to our children for ever, that we may do all the words of this law.