And by the way, think of a child whenever you learn language, the way children acquire language.. they don't think of advanced or basic grammar they just learn whatever they hear and they imitate. There are children of age even below 5 who know how to use the word "apparently" you may search "the apparently kid" over the internet and ask yourself how did that child learn a language without knowing the "rules". My point is not to stress out and be afraid of English language, no one can tell you specifically where to start from. You can use textbooks but even Michael Swan claims that if he were to hire himself as his research assistant, he would have turned himself down. These are his words on his own website. So learn the language in a natural way and don't categories anything as a "basic" or "advanced" level - anyone can learn anything at any instant and no one knows everything. What seems basic to some are advanced to others and what is advanced to others is basic to some.