I've just got Altium Designer, and while I was searching for some components I discovered that I only have two libraries:
Is there any way I can add the default libraries to Altium?
MiscellaneousDevices.IntLib and MiscellaneousConnectors.IntLib are the default libraries for Altium. Other libraries you would either need to download independently or, better yet, create your own. I always create my own libraries, you can find my tutorial here: https://www.youtube.com/watch?v=-kyY25CGJtM
Alternatively you can download non-default libraries from Altium's website:
and install them yourself. Keep in mind that the above link may include out-of-date components, so use them at your own risk. I don't imagine they would change much though, so you're probably fine.