Built-in Mac apps that will help...
Your Mac has several useful software applications bundled with the operating system that can help if you’re having trouble.
Activity Monitor
Found in Applications > Utilities, Activity Monitor shows the processes currently running on your Mac and what resources they’re taking up. Click on one and click the ‘X’ in the Toolbar to stop one that’s not working properly.
Console
Also found in Applications > Utilities, the Console gives handy data such as crash reports, diagnostics and more. This can be very useful when corresponding with a tech support team, who might need this information.
About This Mac
If you need to find out what Mac you have, how much memory it has and other such information, in the Apple menu, select About This Mac. The model, processor, year of manufacture and other information are shown. Click ‘More Info’ for more.
Terminal