Setting up the Firewall: Problems, failure, grief

OK, so I asked a question under a previous log in, which for some reason was no longer accepted, so I had to create a new account ( my email address was not even accepted), but to continue…
I am using mate 16.04.3 32 bit, ( I mistakenly said it was 16.04.1).
I have wifi via a netgear router. Connected to the routers usb port is a thumbdrive.
When the firewall is turned on ( I have not defined any rules yet as I am new to linux ) I do not have access to the thumb drive. When I turn off the firewall, I have access to the thumb drive.
Specifically, when firewall is on, when I click on Browse Network, I see “Windows Network”. When I double click on this nothing happens. When I turn off the firewall, I double click browse network and get “Workgroup”. Double clicking this I get “ReadyShare” ( which is a NetGear thing). When I double click on this I get “USB_Storage”. Double clicking this I get the “Transfers” folder where my files are. I tried several of the preconfigured rules, and of course, nothing worked. Sorry for being so wordy but I don’t know how much information will be helpful. Like I said, I am new to linux.
thanks…

You’d get more help on the Forums or Ask Ubuntu, than you will here, as this is not a support form. Some one will be along shortly to close this thread.