There are also some microcontroller architectures worth considering:
* Intel 8051, dating from 1980. You can still buy e.g. the CH559, based on the same architecture with an USB interface retrofitted somehow.
* AVR 8-bit architecture. Readily available in (older) Arduinos or easy to handle chip packages.
For modern architectures, reading skills can be very valuable, as they allow you to chase bugs beyond the high level language border. Astonishes your friends & confounds your enemies. Writing is decidedly more niche.