Here's a couple that I found from companies I've experience with and enjoyed.
Seeed Studio has their Grove ecosystem. They have a starter kit here: https://www.seeedstudio.com/Grove-Beginner-Kit-for-Arduino-p...
Adafruit have an Arduino-compatible called Metro. They have a starter kit here: https://www.adafruit.com/product/170
SparkFun have a pretty straightforward LEDs and buttons kinda kit here: https://www.sparkfun.com/products/18577
Honestly, they're all a good start.
Alternatively, I'd consider an RPi 400 if you want a more Commadore 64 (all-in-one PC to tinker with) approach.