They wouldn’t find much on my flip phone.
Yup, I turn on my flip phone maybe twice a month. No texts, no apps, no internet searches, maybe just six calls in/out a year. A truth wealth of info for law enforcement.
If they are interested in the fact I just snagged a third printing Nancy Drew volume eight then they can pull that.
But if they are interested in who I bought it from or who I sold it to they are going to have to get a warrant for my records. All of that is kept on a air gap computer.