I don't know much about cars, but I think you should probarly go get it sorted out by a mechanic or just buy another car.
There's a switch when you push the break to take the car out of park. Sometimes it says shift lock by the shifter. Have that checked. You could also have a faulty injector. How's your gas mileage lol
All this car talk. The only thing I can do is change a flat.. Not really, but I can cause a flat. That has to count for something.
Stay away from the jiff. That company is known for screwing people over. Basic things you can do right now, look at the oil filter to see if it was even touched, and the color and oil level on the dipstick. I don't understand how the girl you bought it from could have messed with the timing, and for all I know having the timing off by one or two teeth would just make it run like crap, and not just give it starting/acceleration issues. $115 is ridiculous for just that. Now swap in an sr20ve and be done with it lol.