Doesn't sound like you're hacked really.
don't: ..run old versions of android (upgrade your devices - upgrade hardware if you can't run latest software) ..install apps from non-appstore sources, be vary of malicious appstore apps as well (read reviews, do research before install, generally avoid "freebie" versions of paid software). ..surf on strange pages, click strange links or scan QR-codes ..have bluetooth/wifi/nfc on when not needed ..connect to unsecure free wi-fi, ever. ..don't use public USB loading stations (airports, malls etc). ..have sensible information on your phone/tablet.
do ..use encrypted device / sd-card ..use passphrase to lock the device screen ..use remote wipe/anti-theft service (most AV-vendors offer this) ..keep backups ..consider using a VPN service for those moments you can't avoid connecting to unsecure wi-fi.
That's it for starters.