Choose Window ▸ Pages (F12). Masters are listed at the top, document pages below. Click a page to select it, double-click to go to it, drag a page to move it. Layout ▸ Go to Page… (Ctrl+J) jumps to a page by number; Shift+Page Up and Shift+Page Down go to the previous and the next page.
Use Layout ▸ Pages ▸ Add Page (Ctrl+Shift+P), Insert Pages…, Delete Pages, Move Pages… and Duplicate Spread, or the buttons at the foot of the Pages palette.
Create a master with New Master… in the Pages palette menu, optionally based on another master. Apply a master by dragging it onto a page, or with Layout ▸ Pages ▸ Apply Master to Pages…. Everything on a master appears on the pages that use it.
Ctrl+Shift-click an item that comes from the master to make it editable on that page only; Layout ▸ Pages ▸ Override All Master Page Items (Ctrl+Alt+Shift+L) does it for every master item of the page. Remove All Local Overrides (Ctrl+Shift+F2) puts the page back to what the master says.
Layout ▸ Numbering & Section Options… starts a new section, sets its first page number and its numbering style. Type ▸ Insert Special Character ▸ Special Character ▸ Markers ▸ Current Page Number (Ctrl+Alt+Shift+N) puts the page number in a text frame, usually on a master.