Pages and Preview questions

Whenever I open Pages or I open a doc that opens in preview (like a PDF), pages (and preview) always open the last several docs that I created in pages or download and looked at in Preview.

Is there any way to avoid this? I would like it when I open pages to create a new doc that just pages opens and no docs. is this possible?

Is it possible to open a PDF or similar doc and not have the last however many open in preview?

Not huge issues but pesky ones nonetheless.
Thanks