[leros]

Assuming you're interested in embedded software (pure electronics is it's own thing):

Unless you're already a competent C++ developer, I would start with getting either an ESP8266 or ESP32 and making some simple projects in Arduino IDE by stitching libraries together. You can do a lot with various sensors, actuators, and a bit of simple glue code. Getting outside that simplified Arduino world requires additional learning curves so have fun there first if you can.

I'm a full stack developer and I code in many languages but I haven't had to do any low level C++ code in a while and I'm finding that my biggest hurdle as I'm getting into a complicated embedded project where there aren't libraries for what I'm trying to do.

Of course there are frameworks for programming ESPs in Lua, Micro Python, and JavaScript (Espruino) but those have their own learning curves and limited available libraries too.