Focus on the popular stuff: C on AtMegas, Real time Linux on rasperry pi's. That's something where there are tons of tutorials and books. Forget about fancyness

Focus on the popular stuff: C on AtMegas, Real time Linux on rasperry pi's. That's something where there are tons of tutorials and books. Forget about fancyness in the moment. Instead, if your future company does Qt, learn Qt. It's easy to learn In a few days if you are familiar with C++ (or Python, respectively). If you feel the urge to learn some theoretical background about TCP/IP or so, I think again two weeks are doable. Of course two weeks cannot replace years of practice.