1st gear is engaged by shifting into L at a full stop or by flooring the accelerator at low speed. So one stops, shifts into L - starts off, shifts up to S and immediately back to L to hold 2nd gear, then shifts up to S for 3rd, then to D for 4th.
Your car idles in and starts off in 2nd gear by default; that's so it doesn't creep at idle while waiting for traffic etc. The newer models idle in 2nd but immediately down shift to 1st upon a press of the accelerator.
Shift Quality: The transmission has a vacuum powered shift modulator that's designed to provide soft shifts on light throttle and harsh shifts - no modulation - at full throttle acceleration.
The MORE vacuum at the modulator the SOFTER the shift. So a vacuum leak from a broken or disconnected vacuum line will result in hard shifts. Start at the transmission's right side look for the modulator and a plastic vacuum line attached to it, follow the line up to the engine.
Shift Points: The transmission is "told" the throttle position by a rod, cable or vacuum line - I don't know which your model uses - so the transmission will "know" when to shift appropriately. Take a look at the throttle linkage to see if there's a rod or cable down to the right side of the transmission. If so, come back and I'll tell you how to check its adjustment.