Questions regarding Pages on Mac

macOS and Mac Apps

Dear All the Apple vis members,
I'm Govind From India.
Thank you so much Tyler for recording a very productive and a useful podcast on pages. It's quite helpful when I was struggling to use pages comfortably on my Mac. No I have few more questions regarding the same.
1. How to draw margins and boders on page while printing a document on Mac?
2. How to design a letter: for ex: to leave a certain amount of distance in a particular line to write (to and from) addresses while writing letters. We can do it on windows with tab key. If you press the tab key, it anounces the number of centimeters in a particular line. Is it possible to do the same on Mac pages?
3. How to create headdings in pages document? In earlier versions of pages, we were able by selecting a line and come out of the document and go right pick a heading from the format button, now this seems to have been changed by Appple in their recent update to pages.
4. Last: Any good tutorial on using Numbers and Keynote on Mac? I'm an English teacher and I constantly need to use these apps on my Mac.