Just like the article, there's a huge amount of hobbyist-accessible projects on youtube, you can click around the recommended videos.

Grab a servo and start playing with it.

https://hackaday.com/ - cool projects and interesting stuff https://news.sparkfun.com/tags/tutorial - tutorials on embedded software, electronics, etc. https://learn.adafruit.com/ - electronics tutorials

To begin with you can get a cheap robotic kit from Amazon, there are many of them, and put it together. That's probably the easiest and fastest way. From here you can read more about servos and controllers, modify its mechanics and software.