I am new to trading and have been reading Technical Analysis by Julie R. Dahlquist. Now this book is throwing breadth and sentiment indicators at me by the dozen. I want to start studying data to see if any of these work. The problem is I don't know where to find the data for free. Would anyone recommend a data platform, excel, both, or is there some other place to get free data that could be reproduced as a graph in excel? Real time data would probably cost $ so that isn't necessary.