previously experience with SPSS and Excel for statistical data analysis. But now, want a full guideline about my goal. I have struck because online have huge courses, articles, books, etc but I can't sure where I get started! Your valuable guide maybe helps me get my goal easier. Thanks, Advance.
As your already experienced, I think that the only way to really learn something is taking some risks and accepting that sometimes the best way is the long one.
I´m learning R too. Hopping to help you with your ambicions, try searching some course in Coursera. You´ll find allot of courses there, and the best is that in some cases, if your aren´t interested in paying to get a certificate, still is possible to take the course per se.
Good luck!