When you have two or more keyboard layouts on macOS (e.g. US, Dvorak) then the only way how to switch between them is to click the menu in the upper right corner. It’s not very convenient. On Windows you can use Alt + Shift to switch the layout.
The keyboard shortcut to switch between layouts is by default disabled. You have to enable it.
Go to System Preferences, click Keyboard, click tab Shortcuts, click item Input Sources, check Select next source in Input menu.
Now you can switch keyboard layout by Control + Option + Space
You can also edit the shortcut and use your own.