Keep your practice contained
Use virtual machines or a dedicated isolated network. Start with intentionally vulnerable training targets that explicitly permit testing. Never point scanning tools at public systems or networks you do not own or have written authorization to assess.
Give your lab a simple structure
Create a snapshot before each exercise, separate target and analyst machines, and keep a short note of the goal. A resettable lab makes it easier to compare results and recover from mistakes.
Learn the defensive side too
Capture a baseline, review the logs, and ask what a defender could observe. A useful security lab teaches you how to improve detection and reduce risk—not just how to run tools.