I know that this is a textbook essentially and that I should probably trust what it says, I do want to note that I'm not too sure about how good VPNs actually are. For every time I have seen a source advertise VPNs I have also seen people who make careers out of technology say that VPNs are really only good for accessing geolocked content. Like say if Netflix had your favorite show in their European version but not the US. From what I know, so long as a website has a lock in URL and you aren't already hacked you should be fine. It is safer to not use sensitive information over open wifi but you also won't be hacked immediately as most of the VPN ads will say you are. I could be wrong of course, I am not an expert in this.