You don't need to do anything. The Start Reading location is set automatically. It's just the bots figuring out whether your first page is a title page--which doesn't "count" as a KENP--and so on, so your actually KENP page numbers in the book may go up or down by a few.
You won't get paid for either sales or pages-read until 2 months after the end of the month in which you make a sale or have pages-read. The amount you've earned from pages-read never shows up below the graph, because the amount varies month to month (but usually about half a cent a page, or a little less). You'll be able to see exactly how much your January pages-read earned you on February 15, when the January prior-month report is finalized.
Read the thread in this forum, "Know your Payments." It will help you.