HTML | CSS | Learning basics before I go for any frameworks

I am still trying to solve the newbie challenges using only html and css but I find it really hard sometimes to produce clean and dry code and at this point I am not sure if I should dive even dipper in basic css and general rules of writing clean code or should I try to use frameworks or other technologies to make my code better. I am asking from the position of someone who hopes to get a junior dev job within next year.