3 Answers
+ 6
yes, without html/css and eventually javascript knowlendge you cannot be able to build html document by yourself (you could only serve/use static files/templates done by others...
html/css and javascript course here are enough to get started ;)
however, if you want to deep learn, you must multiply sources after that ^^
+ 1
sure! You can just consider have intermediate JavaScript skills but advanced HTML, CSS and Django are a must. For Django go ahead with blind eyez to zappycode.com by Nick Walter who has brilliant teaching mehod. For HTML CSS JavaScript, SoloLearn is enough along with some external resources such as w3schools. Again to be Django developer you don't need master JavaScript level.