I have a 350z for almost 7 months an american edition convertible 350 roadster automatic gearbox

i recently had a radiator problem and i had to change the whole radiator cause there was pieces and parts of broken things cant really explain what it was but it was blocking the radiator but that problem was fixed.. but then i am now facing another problem, every time i start the car it stalls and turns off and wen i try to start the car it takes a while till it starts and the traction and slip sign comes on.. i really don't know whats causing this but i would really appreciate some advice

thank you