What is the question?
The best advice I can give is be very careful about what apps you download and how you use WiFi. Public WiFi hotspots are not secure so you have to be sure to use secure websites for anything you want to keep private. Also use only secured connections for transferring e-mails.
Not knowing the exact question(s)…..
Use a VPN, if you are not doing so already. There are risks even when you believe you are connecting to a trusted public wifi and believe you are connecting to a website securely., (Beware "free" VPN apps and service. Pay for performance.)
Examine your device's wifi settings. My advice would be to turn wifi off when you are not using it. Set it to prompt you before connecting to a wifi network, exept for your home wifi or office wifi.
Turn off Bluetooth if you are not using it. When using it, if your device has a setting to turn off discoverability, then do it. (If you can turn off discoverability, then there will probably be a way to make your device temporarily discoverable for a short period of time--minutes--so that you can pair with another trusted device.) In the case you are discoverable when Bluetooth is on, don't allow a pairing unless you initiated it, and you know what you are pairing with.
I would not root or jailbreak your device. Don't install apps you don't really need. Search and read up on any apps you are thinking of installing, before you install it. Look at the permissions the app requests.
Set a strong device lock password with an appropriate time out. Manually lock your device when it is out of your sight and when you are sleeping. Don't loan your device to someone. Don't let others use your device.
Privacy and security is a great topic and one we take very seriously. Without knowing the questions, you'll want to take a look over our dedicated Privacy Center | Privacy Statements, Controls, Fraud & Spam page. It's got some insight on how to protect your information. If you have any specific questions, please come back and let us know.