I was in a similar position and the book Rediscovering JavaScript helped me understand syntax and structural changes, which made learning about new frameworks and tools easier.
Had a quick look at it. It skims/oversimplifies some important aspects that are famous in JS community to cause all sorts of issues down the line. Maybe you don't know JS would be better?
Would recommend mdn javascript docs any day. Every once in a while i forget something, i just google "mdn array sort" or some variant of it for my problem, and the answers there are clear
