Not sure I understand the problem.
IF you are talking about placing the shifter in manual 2nd gear with vehicle at a full stop.... then drive off. The GM design is the 4L60E is in 2nd gear when shifter is in manual 2nd gear position.
The trans will not take off from a full stop in first (1st) gear, then shift to 2nd while the shifter is in manual 2nd gear position
Dont worry how old you are... it is the mileage on your body that adds up.