Is it safe?
Yes, buy a phone with cash in person in a different town of yours of course, buy a lot of burning sim cards (anon) you will need them trust me, root the phone with a new firmware and you're ready to go.
Data is always better, more convenient and usually faster than wifi you can use id changer on the browser that you are using.
You can use vpn, but i would recommend that only if you can't find cards on your city or at least state, this way you will not need a vpn and you will be more "legit".
Disassemble the phone (battery and sim) at least 30 mins before you are in your way on home, and again assemble it 30 mins after you're gone for your carding adventure don't have it lying around your house while it's assemble even if it's not powered on and don't card in your home, the phone should only be powered up (assemble) when you are in your "working" area and that's it.