You can do what is mentioned above. However, you can also just copy your existing company over to a "TRAINING TEST COMPANY" so it has all your real info in it. Then just open your new file using the QB file dialog. 

We do this all the time for training and it works well. Since it has our company info already in it, it provides better training. 

One word of caution - make sure your employees are working in the real company when necessary and training only during training - we changed the colors of the test company so that they are very different than real company so it's obvious.