Generate user list in select menu

Hi guys!

I’ve to develop a custom report software.
The first thing, is this. I’ve three membership: gold, silver and free. My client should select an option from a select menu (for example only free membership) and the software should print only the free membership.

I know that this could be done with the user table of Wordpress, but I’ve this request.
The second is more “complex”. I’ve to get all the orders of Woocommerce that a specific membership had done.

For example: show me the orders of Free membership. What Id or data I’ve to insert in Woocoommerce query?