Hey Virginia,
first of all, thank you for the purchase!
I will answer your questions in the same order:
1). If you are using the latest version of WordPress (3.6), you should check the “Main Menu Above Content” checkbox under the “Theme Locations” label in the “Menu Settings” area just under the menu constructor; in earlier versions of WordPress you’d need to choose your created menu from the “Main Menu Above Content” drop-down in the “Theme Locations” box, which is located in the top left corner of the “Appearance -> Menus” admin page. Information on the menus can also be found on page 8 of the theme manual.
2). The layouts for a particular page can be chosen from the “Page Attributes” box on the right-hand-side of the page editor screen; locate the “Template” drop-down and choose the layout you need; do not forget to save your changes! More information on page layouts, together with screenshots, can be found on pages 3-4 of the theme manual.
Please let me know if this helps!
Sincerely,
Andrew / Satori Studio