I turn on my car and it turns off within seconds. I drive car and sometimes when I am at a stop it turns off. When I'm driving it wants to turn off and tugs and goes with check engine light coming on and off quick.

IF check engine light flashes while you have it running/driving , you are lucky it hasn't completely stopped on you yet. Get it to a shop , BEFORE it craps out entirely and have the misfire/stall properly diagnosed. With those symptoms , it would be much easier and cost effective for someone experienced to look at it 'first-hand' , rather than on-line guesses! AND it might keep you from having to buy an engine or car.