Public WiFi hotspots are unencrypted, meaning that snoopers and hackers can easily access your device. This gives them access to your accounts, photos, videos, and even credit card information. You could also be a victim of a man-in-the-middle attack. This happens when hackers create hotspots with a deceiving name (like "Starbucks Free WiFi") specifically to steal information from the people who log on. Other dangers of WiFi hotspots are Packet Sniffing and Session Hijacking. The best way to protect yourself against these dangers is by using a reliable VPN. I’d recommend ExpressVPN as it comes with strong encryption and advanced security features that really free VPNs sometimes can't offer. You can test it out risk-free because it comes with a money-back guarantee. This way, you can browse the web safely while using public WiFi.