How do I make different heading from a single master on multiple pages?

You need to insert a Text Variable on the Parent Pages for Running Heads, typically running heads based on Paragraph Styles work best. But you can also choose Character Style.

In this example I'm focussing on running heads with paragraph styles.

First: You'll need Paragraph Styles within your text

Then go to your Parent Page

Create a text frame where your Running Header should go

Put on both pages

You will see it now

Apply that Paragraph style to other headings to update on each relevant page