Free wifi is abundant in most destinations: cafes and coffee chains, shopping malls, airports, many hotels and hostels obviously, fast-food chains, and increasingly public networks in city centers, stations, and on some buses and trains. Some countries also run official free tourist wifi networks with hotspots at major sights, registered once and usable everywhere. Coverage thins out fast in rural areas, so the pattern is feast in cities, famine in the countryside.
On security, sensible caution beats paranoia. The real risks on open networks are fake hotspots with plausible names and snooping on unencrypted traffic. Practical hygiene: confirm the exact network name with staff, prefer networks with a password over fully open ones, keep your phone and apps updated since modern HTTPS encrypts most traffic anyway, avoid logging into banking on public wifi or use your banking app rather than a browser, and turn off auto-join for open networks.