My answer is pretty generic, else I could recompose the user manual.
If you have questions, don’t hesitate, ask away. Styles – Why? What for? etc.
There are also other threads with the same question on the forum. You may want to search for those, likely you’d find many – if not all – of the answers you need.
Did you put a style everywhere ? (You shouldn’t)
Do you actually want indents everywhere ? – Text messages with a bigger one ? Or just the text messages ?
Please show the left edge of the page on future screenshots.
(I’ll ask a moderator to allow you to post screenshots directly, if future ones are needed. @AmberV )
I wonder if some of this might be chalked up to observing issues caused by this bug. If so, if it is a doubling of indents you are getting in ebooks when making it look right in PDF, then try to aim for getting the PDF right, and use the workaround given in that thread for ebooks.