There is no better way to learn electronics, IoT, and programming than building your own things. We have already covered plenty of cool smart mirrors here in the past. The Ornate Magic Mirror project shows you how you can build your own. It was made using a 32″ TV, an affordable frame, fans, and a few other parts.
The project is inspired by MagicMirror, which is an open source modular smart mirror platform. You can load a bunch of cool modules on this, such as news, time, Google Calendar, and PIR sensor. More info is available in Instructables.