I failed my driving test, any tips for the next one?

Failed on going too slow (20 in a 30 but hilly, couldnt see round corners, and parked cars everywhere area) i didnt signal once when i pulled out from a parked position even though nobody was around and i also didnt check my left door mirror once when i left a roundabout. i think i was just down for a fail that day because they counted them all as serious not minors. i dont really get nervous but im so desperate to drive, i can drive better than quite a few of my friends who had ped their tests first time! thanks