Hi Jesse
That's a good question to which I can't give you a solid answer. I don't know of any online courses or institutions which offer such classes.
What I will say, however, is that once you start taking hormones and you start seeing and feeling the changes, you might naturally move and exist in a more feminine state. Your pre transition self will never leave you but it will take on a more feminine form. Also, once you start living full time, you will start to develop your own unique mannerisms which you will adopt and will soon come naturally to you.
Hope this helps