Command + Space for Spotlight
Pressing the Command and Space keys at the same time on your keyboard opens up Spotlight, which is your general solutions-finder on macOS.
If you’ve ever used Cortana on Windows 10, it works a lot like that. You can type in whatever you want – it could be a file name, a location, a currency conversion, a quick math problem, the time in Hong Kong, an app you want to find – you get the idea.
It’s your go-to solution for finding things out, and it’s usually quite a bit faster than trying to Google something on your own.