Power stirring

Hi I recently was driving and as I turned and park to drop my friend off my power steering went off and luckly I wasn't in a main road I turned my car off and then turned it back on and the car was fine now whenever I'm on D or R it shakes a little to much i don't know if it's just me since I was kinda freaked out or that's actually common I would appreciate some help I'm worried since I just bought the car