How can I assign the default keyboard shortcuts for SketchUp?

Answer 1

Default keyboard shortcuts are already assigned when SketchUp when installed.

To create, change and remove keyboard shortcuts in SketchUp, from the top line menu (in Windows), click Window then Preferences. You will see a popup window titled SketchUp Preferences. On the left side click on Shortcuts. On the right side of the Preferences window you should see all the SketchUp commands and their currently assigned shortcuts both default and custom. From there you can make any modifications you want.

It should be noted that not all keyboard combinations are allowed because they are either reserved by the operating system or SketchUp (i.e. <ctrl><p>). However there are more than enough keyboard combinations available than you will probably ever require.