shifting help

I have a 96 camaro rs runs great well when i start it but if a stop at a stop light then it seems like the brakes are stuck or it doesnt get first gear but when i hit the gas it goes straight to second gear . after that it runs great until i stop again. but if i shut it off and re start it shifts fine until i stop again. what could this bee. my service engine soon light is on. oh some times i smell like either burnt oil or something similar but only when i accelerate the car to get it to second gear.please respond soon. thank you.

#1 find out the code(s) stored that are making the light come on.
Check trans fluid to see if it is discolored or not and if the level is good.