Square waves or pulses are normally used for timebase calibration because they are easier to line up with the graticule than sine waves.
The timebase settings are in groups with separate calibrations but usually you only need to calibrate one of them for the others to meet specifications because they all track. The same goes for the vertical calibration. If the calibration is off, then usually all deflection settings are off by the same amount unless something has failed.
Before I got a dedicated oscilloscope amplitude calibrator and time mark generator, I used a 2 MHz function generator, frequency counter, AC voltmeter, and switched attenuator to do oscilloscope calibration.