In system menu Help -> Controls Help you can find main combinations that would ease your work with the Planner 5D.
However, if you are using touchpad, that doesn't really changes combinations for you. You need to check your touchpad settings to understand which gestures simulates the right and left button and the scroll on the mouse.
You can find that information in System Preferences -> Touchpad.
Usually those are the settings:
- the left mouse button = tap with one finger;
- the right mouse button = tap with two fingers;
- scroll = moving up and down the touchpad with two fingers.