How to fully secure and harden a Ubuntu 20.04 laptop?

[mahesh]

Hi,
I am trying to secure my Ubuntu 20.04 laptop to make sure it does not connect to the internet, either by accident or through an attack. (I use another computer for research on the internet).

So far I have done the following:
-I have disabled ethernet, wifi, Bluetooth in the bios and only have the USB port enabled for my USB sticks
-I have activated the uncomplicated firewall using the command sudo ufw enable
-I thought it might be a good idea to generate logs, using sudo ufw logging on
-I don't want any ports to be open and wonder if I need to execute any particular commands to ensure no port can be accessed?
-I encrypted the hard drive when I installed Ubuntu 20.04
-What kind of passwords do I definitely need to set up?
-Is there anything else I need to adjust in the bios?

Thanks for the tips.