Im learning Web Development...maybe??

i have been doing website stuff for a while, basically just from spending 100's hours on my pc. Ive read HTML books and many more. All the stuff i find tells me how to do stuff but dosent really explain why it all works! They say its a "mark up" languages, but never explain what that is, whats a framework?, whats syntax?, what are javascript libraries? These are some of the things i want to learn to have a solid foundation in web development. 9 out of 10 times i can get things to work, but i dont know why they work! Can i get opinions on wheres the best place to START! Basically i need step 1. Thanks.