If you truly want to learn, I suggest joining a local FRC Robotics team as a new/junior mentor. If you simply ask the students to show you what they have been working on, you may be inspired to join in and help. You'll learn together... mechanical, electrical, programming, etc.

A short overview of what FIRST robotics is: https://www.youtube.com/watch?v=Jd29kzjclV0

A web based tool to search for local teams: https://www.firstinspires.org/team-event-search#type=teams&s...

I've been volunteering as a FIRST mentor for the last nine years and have learned more about robotics from the students than I did in my master's program or on my own.