Is there a default keyboard shortcut to open the launchpad?

Yes, it is located in the Applications folder and it does open when I double click on it.

I did not change the key assignments for the F4 key, as I mentioned above, I just went and assigned it now and it worked after I assigned it.

I'm new to Mac and just wanted to use the default shortcuts whenever they exist, that's why I was asking.

Not sure the assignment is not on my MacBook, it may be the updated OS or it could be something I installed. Not sure.

Anyway, it works now and I guess by assigning the F4 key, I'm using the default option.

didn't work

That's what I did and it doesn't work. Other functions keys work as they are supposed to (e.g., F12).

It doesn't look like F4 is assigned to the launchpad.

I just went into system settings and assigned the F4 function to the launchpad. It now works. Was wondering if there is another key assigned by default but it doesn't look like it.