It appears heading size defaults are all the same size.
For example H6 Tag and H3 tag are the same size. Why is that? Normally headings should be largest size H1 down to smallest size H6. How can i fix this or change the individual H tag sizes?
You can change the font by means of Advanced typography option, which allows to choose the item from a drop-down or insert your custom CSS class. Please navigate to the Theme Settings > Typography > Advanced Typography.