That depends on how well you absorb the lessons, how many lessons you take, and how much you can spend on lessons. The DSA recommends that you take at least 47 hours of professionally supervised driving instructions before applying for your license, but most people will require more time to fully master the skill and become confident enough with their general driving ability.
There’s a study that shows men need at least 17 lessons to pass their driving tests, while women need 21 to do the same. Personally, I think it all depends on how eager you are to learn and how well you listen to the instructions given to you. I took driving lessons at a school here in Croydon, and I was intent on doing well in my driving tests. I managed to pass both the theoretical and practical parts of the test with just 50 hours of lessons under my best. I learned quite a bit from taking those lessons, so if you’re interested, the school I enrolled at was Apex Driving School, and their website is www.apexdrivingschool.co.uk.