Car Tech: 2008 jeep liberty

2008 jeep liberty

help i just bought a 2008 jeep liberty 29 days ago . ive signed a contract but i still have not given deposit. im a single mom and scared. i took the jeep back in because it seemed to hesitate in reverse and when driving forward. should i be alarmed by this ? or is this normal for the 2008 jeep. the dealership told me that it need its 15000 mile check . they also said it could a problem with throttle. should i be having this kind of problem ? i purchased at 14500 mile should i already be required to do maintenance? PLEASE HELP