So what do you need to start driving?
You must obtain a provisional driving licence; application forms via Post Office or online: www.gov.uk/apply-first-provisional-driving-licence. To apply, you must be at least 17 years of age* and satisfy certain medical conditions (details can be found on the forms).
If you are already a holder of an International Full Driving licence from an EU or Commonwealth country, then you may well be entitled to exchange this for a full UK licence, which you must normally do within a year of becoming resident in UK. If you are holder of an International Driving licence from a non EU or Commonwealth country, then you may well need to take both UK Driving Theory and Practical Driving Tests within 1 year of becoming resident in UK if you intend to keep driving after this period. For the first year after becoming a UK resident you may drive as any tourist may, subject to UK regulations.*Certain disabilities can in fact entitle 16 year olds to a provisional licence.