I would say that you need to start looking into frameworks if your goal is to build a custom CMS. I have done this on many production projects using the MEAN stack (MySQL, Loopback, Ng2, and Node). There is a lot to take on if you go this route if you are not familiar with any of these. I would suggest starting with Loopback + Node, and then move to Ng2. If this is to overwhelming, I would focus a lot on @sdiq points :)