Seriously? The files @Geo posted are plugins to be used in SketchUp Make or SketchUp Pro. The post you are referring to was made over three years ago; well before SketchUp Free was even mentioned.
If you are using SketchUp Free as indicated in your profile, the rbz files won’t help you out. You can look at the Quick Reference card to get an idea of the keyboard shortcuts. You can get the Quick Reference card from the link Geo provided.
Based on what you wrote in your profile, you need to be using SketchUp Pro anyway. Then you could use the rbz files that you referenced.