You have the right to a rest break of 20 minutes where your working day is longer than 6 hours. If you are under 18, however, you are entitled to a 30-minute break after working 4.5 hours.
You should receive 5.6 weeks' paid holiday every year. In the past, some employment agencies have tried getting round this by saying that your hourly pay rate includes holiday pay and that they therefore do not have to give extra pay if you take leave. However, thanks to a decision by the Court of Justice of the European Union, this practice has been ruled unlawful, and your employer has to pay you on days which you take as holiday.
Note that practices which you may be used to, such as 13th (or 14th) month payments, and holiday subsidy, are not normal in Britain.