No, you should learn ES3 before you learn ES5. (don't take that seriously)
Please, do not waste your time on the legacy and history of feature sets. As a beginner, everything JS you learn is new to you, so just take the latest and learn it. There is absolutely no need to know that in legacy JS you did not have Arrow Functions. They are there, they are available, they are useful, so just learn them as part of your experience. Don't make your life harder than it is ;)
Also check out this old discussion on the topic.