Apply for a provisional license straight away (this will allow you to drive, but you will need to have 'L' plates on the car and be accompanied by someone with a full UK driving license), get a book (highway code? -not taken the new written type test, so I don't know what exactly you need to learn) and book some lessons with an instructor and ask them what they think of your driving and if they think that you are ready for a test. As soon as they say you are ready, then apply for a driving test and book the written exam.