Connect the probe to channel 1 (or channel 2) and connect it to the calibrator output (where you have it already).
Set the scope for 1 ms and 100 mV. Best to turn on the 20 MHz bandwidth limit too. Keep the VAR (variable) setting on the VOLTS/DIV knob turned (clicked) to off.
Adjust the intensity on the display to get a sharp trace (might be good already, your photo looks a bit bright but that might just be the camera/photo).
Assuming your probe has a compensation adjustment (looks like it does), adjust the probe (preferably with a small nylon or some non-metallic screwdriver blade) to make nice sharp square corners on the displayed waveform. You can use the VERTICAL POSITION knob for the respective channel to get the waveform to line up nicely on the graticule to help you see when the calibration setting produces very sharp corners.
You can check/adjust the waveform on both AC and DC settings for 1 M ohm.
Enjoy the 2465A! It's a classic.
Edit: I think the main issue is that it looks like the scope might be set for 50 ns (hard to see for sure in the photo); try 1 ms and you are likely to get a much sharper waveform to help with probe calibration. Once you get it dialed in at 1 ms then speed up the SEC/DIV setting and watch what happens to the waveform as you step through each setting from 1 ms to 50 ns.
- once you get it calibrated post another photo - if it's all working properly you should (will likely) have very sharp edges.
As a next step you can use the cursors to measure from rising edge to rising edge, etc. at various SEC/DIV settings and get a feel for frequency, periods, etc. This is a great scope for learning lots of fundamentals. Enjoy!!
PS, VERY COOL
to have a new EEVer from Antarctica! Welcome!!!