In England you have to have been married at least 1 year and separated for at least 2 years before applying for divorce if you both want the divorce to go ahead. If one of you does not want a divorce the separation must be 5 years long. The separation usually starts when one of you moves to a different address and can start within the first year of marriage.
You can find out about the forms required here
http://www.hmcourts-service.gov.uk/infoabout/d ivorce/index.htm
If there is any dispute you may need a lawyer. The courts need to know that you have made clear and valid arrangements for any children and that there is agreement about the division of any assets (or debts) from the marriage. Your local CAB will often help with filling in the forms as the court officials will give you no legal help.