Is there a shortcut key to bring up the Launch Pad on an older apple keyboard?
Solution 1:
You could simply configure a shortcut of your liking for it in:
System Preferences > Keyboard > Keyboard Shortcuts > Launchpad & Dock
Solution 2:
Check in System Preferences > Mission Control what key is assigned for Launchpad. You can customize the settings of course.
Note that per default pressing F11 for example will work as a media key (change volume in your case). So you need to press fn+F11 instead.