I have started my PPL, and although engine failures are rare, they do happen. That is why you have to comolete lesson 16, simulated loss of engine and know how to calm your passengers, tell them what you are going to do, and then pick out your landing spot.
You have a fair bit of time to do this, even from 2000 ft. We were buzzing large fields for a good hour practising this.
There are more potentially dangerous aspects of PPL than losing the engine, such as turns with flaps at low speed and altitude.
So dont worry and go for it.