View menu & preview

The View menu lets you hide panels to give the canvas more room.

PanelShortcut
ToolbarCmd/Ctrl + 1
TimelineCmd/Ctrl + 2
Tool SettingsCmd/Ctrl + 3

Preview window

Preview opens a small floating window that shows only the canvas at the current frame. Its Play button loops the animation without moving the editor's playhead, so you can keep drawing while you watch. Close it with its close button.

Onion skin

Onion skin is also toggled from the View menu. See Timeline & layers.