Both topics are covered extensively in both training and the manual set. LoadRunner can be a pretty dangerouns thing to play around with without having some formal instruction on. It's been known to take down both test and production systems, consume available usable bandwidth of corporate networks and in general cause havoc. These tools are designed to replace the behavior of up to tens of thousands of users in an environment for testing purposes, so it is like having an army trounce on your resources.
With the proper training you can identify and minimize unintended consequences to your organization when you use performance testing tools. A good in depth read of the docs should address your question, particularly the controller users guide.