I took a Skillshare class by Daniel Walter Scott, who runs Bring Your Own Laptop, called Responsive Web Essentials with HTML5, CSS3 & Bootstrap. I had a great time with this class and really learned a lot. The instructor was engaging and taught in a way that was easy to understand. I learned more than I thought I would, because the class was running an older version of Bootstrap than I was, and I didn’t realize it at first. So, I ended up learning BS 4 & BS 5.