How can I block someone from hacking my phone while they use my hotspot?

ANSWER:
Steps before you turn on your hotspot,

1. In Hotspot setting, click on “set up Wi-Fi hotspot”
2. If you see WPA2 PSK, set up your password so only through logging in the password can share your wifi
3. Make a habit to change/update your password once in a while

You can also check whose devices connected to you and make appropriate action such as deleting/blocking devices connection