TLDR: just use your phone. Yes people causing interference through improper use of the ham bands do get run down by the FCC some of the time. If you do it at low power on some UHF frequency with very few users, probably no one would notice if you didn’t do it too often, but those frequencies are only good for short range communication anyway, so you might as well use your phone. The low frequencies that can travel international distances are more interesting but they are also more closely observed.

If you are ok with short range you can also use LoRA or meshtastic instead of ham bands. Encryption is perfectly fine there.