oh i am so sorry you are so anxious, the hospital local to me starts inductions for primpips in the morning.. can you ask to change to the morning? if you are ripe, and have a good bishops score, then it might not take long at all. and of course you could well go into labour before your induction, furthermore, you do not have to agree to be induced , you can ask for expectant management.
what will most likely happen is, you will be given a prostoglandin gel which is inserted into the vagina, and helps ripen the cervix, and get it soft and dilating. it might take more than one dose, and htey are given 6 hours apart, you will be monitored after each dose.
once you are dilated enough, you will be transferred to labour ward for your waters to be broken, which should help stimulate more contractions.
if that does not get you going or your labour is not getting established, you will be given a drip of a synthetic hormone to strenghten the contractions.
have you been offered a stretch and sweep? that can help get you into labour.
there are no set answers, a friend delivered 2 hours after her induction started , another took 24 hours, so there is jsut no way to tell!
best thing to do, is stay as active and upright, mobile as possible once hte process starts, remaining on the bed, lying down does not allow gravity to help you