This is something of a companion to Using createCharStyle.
Although in Scribus there is an implicit character style whenever you create a paragraph style, in Scripter these are two distinct commands, but we'll see how the two can be linked.
Here is the overall picture of syntax:
scribus.createParagraphStyle("name", linespacingmode, linespacing, alignment, leftmargin, rightmargin, gapbefore, gapafter, firstindent, hasdropcap, dropcaplines, dropcapoffset, "charstyle")
As in the companion piece, quotes around a parameter indicate it is a string surrounded by quotes, and the absence of quotes indicates a numerical value.