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Use the security setting in system setting, don't share files and printer, don't use insecure web pages with password unencrypted; privacy browsing in Safari.

Make sure to use secure ports or eMail ; can be configured in Mail setup.

if you want to be fancy open a VPN to your home Internet and route via there ...
 
I would recommend using a VPN service to be sure, especially if you are doing personal banking etc.
 
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