Always right-click on Part 1 and select "Extract Here." The software will automatically "chain" the parts together and pull the data from Part 2 when it reaches that point.
You cannot open "Part 2" by itself. It is like trying to read the middle chapters of a book without the beginning—the file won't make sense to your computer. 2. How to Extract It Correctly
Use a tool like VirusTotal to scan the archive before you extract it.
If you are downloading from file-sharing mirrors, a VPN helps protect your IP address from trackers. Summary