I hear this - or read this - a LOT! Now, a) you might mean that you really want to work with a personal trainer to learn how to improve your workouts; or b) you want to get comfortable in the gym and learn how to effectively create an efficient workout plan that will bring you the results you desire. These are both fantastic reasons to hire a personal trainer.
That being said, if you think it's solely hiring a personal trainer and learning how to workout that is going to result in finally reaching your physique goals, you are sadly mistaken.
It's not the workouts that bring the results. It's the workouts PLUS knowing how to eat to reach your physique goals. Or, if you simply want to lose weight - you don't actually have to "workout" at all. That's where you need to a) either educate yourself on how to tailor your nutrition to fit your physique goals, or b) work with a nutrition/weight loss coach with the knowledge and education to teach you the proper nutrition to get you to those goals.
Being a consistent gym-goer, I am often saddened to watch members work with trainers for MONTHS and to observe very little - if any - change to their physiques. It's NOT that they're not working hard. It's NOT that the personal trainer doesn't know how to train them. It's because the members are not being educated on the proper nutrition (calories, macronutrient partitioning, etc.) to reach their goals.
Bottom line, you can workout until you're blue in the face, or you can pay someone to kick your ass in the gym, but if your nutrition/diet needs are not addressed, you will not get the results you desire.