MCUs
ESP32 with WiFI and Bluetooth. The ESP32 is fantastic and is now my default micro-controller for most projects. However it requires a lot of power to operate and that can create a signifigant challenge for battery powered IoT devices that need to run for a long time. Still, fantastic microcontroller and great for a ton of applications and managing sleep mode properly it can lower power consumption massively.
MSP is not for beginners. Unless you're copying/pasting code, you need to have strong foundations on C, then you could even jump to assembly. Arduino/Raspberry is a good introduction because you have lots of reference material, examples, and bigger community to get started with.