Just need a plane flip phone my LG from att isn't compatible but they have a 3g LG about 30$ and it's 25$ unlimited talk and text not sure what carrier but They referred me to simply wireless because I had the att phone! Need to update anyway it's from 2015 they also have a Android flip phone 4G but I don't want to use data just calls and texts, just open and say hello I understand that 3G never drops and that's what I have now don't need the Android that's what my tablet is for Huawei mate awesome
WiFi is turned off all the time in my Android so there's no danger of it being got at. I turn it on at home if I really need to because I trust my own network. I'm not sure you can find a smart phone without wireless.
You just have to turn it off to prevent running up a data bill. Google will find you and update if you leave it on.