What is exciting enough for you that you'll be able to sustain your interest? There's a lot of learning.

I'm going to maybe diverge from some advice and say try and start with hardware connected to your laptop. That's how I started way back (during the original IBM-PC era and a Data Acquisition Card from IBM). Learn how sensors, motors and actuators work. If you were near me I'd lend you a kit I have sitting around that I got for my kids but I'm sure there are options to hook up some basic I/O (Analog and digital) to your laptop.

I would decouple the embedded aspect from this for now and really many embedded systems are running "real" large computer systems. You can build a lot on your desk and having a "real" computer will take away some of the additional hassle of dealing with various embedded platforms. Once you gain a better understanding of the components you can always move to some embedded setup.

The Art of Electronics is one book I will recommend. I would say though start with a kit and use AI or Google search to get some basic circuits going.