the book i used to learn html and css was "html, css and javascript for dummies". i got it from my local library so you probably can too.
this is a link to a list of all valid css colors.its on pinterest
really anything "for dummies" is useful for learning all sorts of stuff
again "composition for dummies" and "music theory for dummies" are amazing resources for learning how to make good music
i also reccomend learning guitar/uke/bass and piano cause if you put the two together you already have an amazing musical foundation
for music programs i use LMMS and bosca ceoil blue, which is like chrome music lab but advanced
speaking of chrome music lab, its really amazing too. i use it for melodies and stuff, and also inspriation during artists/writers block (whichever one musicians have lol)
i've heard a lot of people say that fl studio is really good, so heres what i know. the free trial has infinte time with all the stuff, but you cant save your projects. the paid version ranges from $99 to $499 depending on what version you get.