Make sure you have a recent RTL-SDR dongle that can have the “Bias T” turn on.
Make a water proof box of some description.
Or set up a test system under a veranda etc.
Aiming the satellite antenna is important.
Make the USB lead from the Raspberry Pi to the RTL dongle no longer than 6 feet to start with.
Get at least a 2 amp power supply for raspberry Pi. The RTL dongle will draw approx 200 ma.
Boot raspberry pi with the Outernet Raspberry Pi 3 image.
The Pi should boot and you will have a WiFi hotspot to log into.
Remember this is a old image of Outernet software but it will get you started.
So far there is no talk of releasing a updated Outernet software for Raspberry pi.
If you like the Outernet you might be better upgrading to a Dreamcatcher board.