I'm not a software engineer, so as more of a hardware guy, Arduino was key in my early learning.

They are super cheap microcontrollers with tons of example code you can piece together to blink LEDs and read sensors and knobs in minutes. You learn and build from there.

It is a lot of fun to get code working and powering something in the real world. You can interface with all kinds of things to make fun protoypes. And, it has a great online community of makers.

I see some good, traditional resources in the other comments, so I'll leave it there.