Howdy, welcome to the forum!
A good place to start is the Troubleshooting Wiki entry. Look through that page for the Engine Log, because that’s where information is stored about all of your macro executions.
If you’re having trouble with that, take a look at my post here where I share a macro designed to show you a list of errors in the last 1,000 (or optionally, 10,000) macro executions, and then take you directly to the action in question.