I know this is going to seem old-fashioned, but I don’t think much of using online tutorials to learn programming languages or platforms. These generally give you no more than a little taste of the language. To really learn a language, you need the equivalent of a “book”, and in many cases, this means a real dead-tree book.
If you want to learn C, read K&R. If you want to learn C++, read Stroustrup. If you want to learn Lisp/Scheme, read SICP. Etc.
If you’re not willing to spend more than $30 and a few hours to learn a language, you probably aren’t going to learn it.