You may adjust Geany's settings using the Edit --> Preferences dialog. Any changes you make there can be applied by hitting either the Apply or the Ok button. These settings will persist between Geany sessions. Note that most settings here have descriptive popup bubble help -- just hover the mouse over the item in question to get help on it.
You may also adjust some View settings (under the View menu) that persist between Geany sessions. The settings under the Document menu, however, are only for the current document and revert to defaults when restarting Geany.
Note, in the paragraphs that follow, the text describing a dialog tab (if present) comes after the screenshot of that tab.
The "Context Activation" setting needs to be documented.
The open files list and the editor tabs are two different ways to switch
between documents using the mouse. When you hit the key combination to
move between tabs, the order is determined by the tab order, not alphabetical
as shown in the open files list (regardless whether or not editor tabs are
visible).
Line wrapping refers to the display of the text in the editor. Currently,
there is no setting to have Geany automatically insert newlines into your
document while you type.
There are some handy commands in here that are not, by default, bound to a key
combination, and may in fact not even be available as a menu item (for example, the
very handy "Hide and show all additional widgets").
For more information see the section called “Keybindings”.