how do I add icons to my dock or home screen

Mac 101: Get Started Using A Mac

drag them from the applications folder and drop them in the dock

if you want it on your dock - go to your applications folder or click on launchpad and drag the app you want to you dock.

To add something to the Dock just drag it there and an Alias will be created. To add to the desktop you must first create an Alias then move/drag/drop it on the desktop.

click on finder and it will be on the lefthand side.