I've got a free wordpress blog, I'de prefer to understand how to change css or place an element to create Code lines colorful, when utilizing a Programation Language or HTML which.

I believe you're searching for this. Simply place in your "visual" editor, not in HTML editor.

[sourcecode language='html']
     Here Goes the code to Higlight

in Language, you can put any kind of Programming Languages, try php, javascript, python, ruby, and much more of these...

Seems like you are speaking about syntax highlighting. Various JavaScript based solutions exist, search for additional.

Should you host your blog yourself you are able to download a syntax highlighting wordpress plugin within the admin section. If it's located on the platform e.g. wordpress.com you're probably unable to download and install plug ins yourself.