Making it safe.
Although macOS is more secure than most other operating systems, the increasing user base for macOS is drawing in hackers. So long as you keep your system up to date with the latest updates from Apple most malware is kept at bay. However it is still possible to get malware (viruses, adware, and spyware) on a Mac that infect other systems on the Mac such as JAVA or third party browsers such as Google Chrome. Plus you could be passing on Windows viruses that do not affect your Mac but...