Your driving age among other things determines how fast your progress in learning to drive will be, obviously the younger you are, the less number of driving lessons you will need before you are ready for the practical road test.
I know that money can be an issue, but the earlier in life you get your full UK licence, the cheaper and less effort it will be for you.
Driving Age podcast.
More driving test tips
How many hours do I need to pass the UK driving test.
What's wrong with cheap driving lessons?