1.front end (client side) :-
it comes as a package of 3
so knowing html/css helps a lot
I can say its important that you know it before moving to js, coz you run your js inside <script> tags which is html.
2. backend (server side) or software :-
I did not. I learnt JS first. From experience, it went fine; however, if you learn just the very basics of HTML and CSS first, then you will probably have more fun doing JS.