if not equipped with a "B" Switch ont he shifter, try putting it in 2, then back to D when you are at a light. it should start off in 1st gear.
My 1992 300Ce has 1st gear start always.
'92 300CE - Sold
2004 C240 - C7 Wheels
2015 ML350 - P1, Pano, Ash poplar wood, Sport Dinamica interior, Running Boards Keyless go.