1988 124 300CE acceleration question

[JasonOne]

I'm a novice driver and was wondering what the best way to get the car moving might be. It's a big, heavy coupe with a heavy 6 cylinder inline motor rated at 177 hp. I would prefer this engine in the 300SL or something but since it's what I've got and it's now running great, thanks to DR. MB Motors who rebuilt and set the throttle linkages, what's the way to accelerate off the line?
From drive and into 3rd and then hit the switch under the pedal? Or drive, hit the switch and then into 3rd?
Thanks for any and all info. I don't want to hurt this car. I'm not one to punch out an old Mercedes but I do enjoy taking it up Pacific Coast Highway at 80mph so far. Not sure what it can really do. 80 seems like its just getting warmed up. Definitely after more maintenance and tuning I would like to take it faster, perhaps up the 5 freeway. Car only has 110K miles and I'm the 3rd owner. The pedal is long and slow, can this be easily adjusted? But in reverse it sure is quick to apply power to those rear wheels.
BTW, what's 2nd gear good for? Mine is high rpms when not loaded. Up hills it seems to load nicely. I dont have the manual with this car. It did come with all other original documents. Only thing missing is the manual. Thank you.

Jason