It sounds like you have everything you need.
NFM is probably what you would want to hear there.
However, seeing activity in the display doesn't mean ham activity. (or voice activity)
If you have any switching power supplies nearby, then you will likely see some 'hash' from them.
There's no activity on that band here right at this time.
But, here's what you can look for.
It's a screen capture of NFM activity on SatCom.
You can see two voice signals.
One at 253.750 MHz and another at 253.850 MHz.
You can pretty much see each syllable and the pauses in speech at both points.
There's one or two more weak signals further up the band.
The others are of unknown modulation or random signals.