Also what is the difference between the "triangular waveform" and the "rising edge" mode. On the second there is nothing on the output.
I don't have or know that specific generator, so I can just offer educated guesses:
The triangular waveform must select regular ramp mode, with the slew rate adjusted by the potentiometer, in a range selected by the set of V/s range buttons. I would expect that there is also a way to change between sawtooth signals, with either rising or falling slope, or symmetrical triangular signals. Maybe the two pots on the far right can adjust the rising vs. falling slope?
The step function is less clear to me. A pure square wave output does not seem to make much sense in a "sweep generator". Seeing that the front panel also talks about "staircase trigger", maybe there is a mode where the ramp is not smmooth but increases in discrete steps, and you adjust the step height instead of the slew rate? [Edit: This mode may need the "staircase trigger" to do anything? Have you tried feeding a signal to that BNC, or pushing the "manual" button there?]