"Sadly i don't fully understand which ones cascade from which."
I don't know if I understand exactly what do you mean by "cascade". In Writer, one can set the properties of a style as "dependent" from other style (Writer calls this "linked"). For example, "text-body" is normally dependent from "default". The wiser thing to do, I think, is to set the minimal common values in "default" and then make other styles depend from "default". For example: Set "default" to Liberation Serif 12 normal style, 1,5 space between lines, etc. Then you can make a "text-body" style dependent on (linked with) "default", but you add indentation for the first line of each paragraph. Again, you want the first paragraph after a heading without indentation and with a big capital first letter: you make another "default-dependent" style, let's say "first paragraph", with all these additional features.
That about dependency among styles. Maybe that is what you call cascading.
But it can also be an automatic shift of style once one changes paragraph, so one doesn't have to be manually swifting among styles all the time. Taking the same example. Imagine you have those "default-dependent" styles I explained above (and some other "heading-dependent" ones). You can tell Writer to sequence these styles in a particular order: you want that, once you have introduced a "Heading 1", the next paragraph is automatically set as "first paragraph", and then, the next one, as "text-body". You can do this by selecting the "Next style" on each style properties: in this case, "heading 1" will have "first paragraph" as "next style"; "first paragraph" will have "text-body" as "next style", and "text-body" will just have "text-body" as next, so each new paragraph after a "text-body" one will remain "text-body" styled.
Now, both of these operations I have described are easily done through the style manager: press 'F11', right-click on the desired style and left-click on "Modify". In the dialog that pops up, select the "Organizer" tab, and there you have both the "linked with" and "next style" boxes.
My advise is to set some minimal style for the default and do not actually apply it directly on your text, but create linked styles with richer features. Thus you will assure coherency (since all styles are dependent on "default"). Same thing for headings: apply a font-size to "Heading", link all other heading styles to it and then modify the font size of each one relatively, if you wish. But do not actually apply "Heading" style to the document: use the linked "Heading 1", "Heading 2", etc. instead.
Anyway, everything is quite clear here: https://wiki.documentfoundation.org/images/8/80/WG4007-WorkingWithStyles.pdf
Hope this helps.
Regards,
Joaquín