To install UBPorts, you can choose between three tools : UBPortsInstaller/CPT/MDT.
However, a common prerequisite is (1) to enable developer mode/ADB debugging on device and (2) to install ADB drivers on computer.
(1) Go to settings, scroll all the way down to About this device (or about this phone) select that, scroll down to build number, and start tapping that fast over and over until it says you’ve unlocked developer
Then go back up one level and now there is a new menu option called options for developers. Select that, then scroll down to USB debugging, switch that on.
Now adb should work on your phones side.
(2) To get adb on your linux pc working with FP2, follow those instructions:
sudo apt-get install android-tools-adb android-tools-fastboot
First you have to install ubuntu-phablet-tools:
sudo apt-get install phablet-tools
Than you have to add your device to your desktop. In my case for the Fairphone 2:
echo "0x2ae5" > ~/.android/adb_usb.ini
Then you have to kill the adb server:
adb kill-server
And than with adb devices you get your adb device listed.
(2b) To get adb on your windows pc working with FP2, follow this other guide.