I'd look online for mechanical engineering courses. If anything you can put together a curriculum and slowly follow it. It's hard to make a recommendation. I

I'd look online for mechanical engineering courses. If anything you can put together a curriculum and slowly follow it. It's hard to make a recommendation. I did not learn mechanical design formally. Also an EE. However, mechanical has always been a part of my life since I was a teenager. The only way I can summarize my path is: doing thousands of projects and constantly learning.