CDDouble's blog on here is a good place to start!! i knew literally nothing but i followed their blog and i've been messing around with it since,, kinda been fixated on coding (⇀‸↼‶)

I personally had a few class last year about html so it kinda helped, but what i would recommend is finding the basics on a youtube tutorial for collar and images and such, and then you can try to copy paste specific elements from already existing code, for exemple in the skins tab or directly from someones preofile with the inspect features on browsers. In any case i sure if you ask some pepople would be glad to tell you how they did theirs :3 Good luck!