You just need a visa of some sort, you will get a 2 year provisional licence. If you have a licence from your country, you will just do the reaction, colour blind, and the alignment tests, plus a medical, which nobody fails and costs next to nothing. I did have an International Driving Permit..
You will watch a daft video for an hour.
You can drive on your UK licence for 90 days. Motor and bike licences are treated separately, including the medical paper..