Thanks for the advice - very good points. My history is that I started in this journey in order to be a javascript guru and focus solely on the functionality of existing websites. This was due to being exposed to a JS specialist at work who modified our site using JS and angular. I used to be a programmer (COBOL / Fortran / Pascal/ Assembly Language) back in the early 1800's, so was taken by the amount of impact he made on the front end for our company using something as simple as javascript..
So I went back to studies to relearn programming and then I discovered HTML and CSS but still thought I would just get through these and still focus on the front end JS functionality. Then of course discovered a strong interest in HTML and CSS and subsequently responsive design. and I realised that it was'nt just about focussing on modifying the front end of existing sites - I could create sites myself and do ok at it.
The single biggest lesson I have learned in terms of responsiveness is to plan the site for the smallest viewport and expand up from that.
Bootstrap is fantastic for aiding the novice programmer, but I would also have to say that JS / JQ is the third arm of website structure - html being the content, css being the style and javascript being the functionality. I am only beginning my journey with this, but have already decided that I want to do this in a professional capacity.
I would completely agree that learning the basics of each modality before going into the more advanced / detailed areas.I would however say I am moderately skilled at javascript and absolutely love the functionality of jQuery.
Also if a person only uses something like Bootstrap - it would be easy to forget core skils and knowledge in the programming modalties and you might become a bootstrap expert but unable to code html or CSS by hand.
Thanks for the kind support through this forum. I enjoy coding but realise that I am still a beginner.
I look forward to learning more from your experience.