Search marriage records UK?

google Free BMD press search and enter details. It is free and covers from 1837 to date.Or Family Search. org, the Mormon site.  Dont forget, finding people is 1% inspiration and 99% perspiration, good luck

Marriage records are not what you should be searching.  You need to search birth records which identify either your mother (using either her maiden name or her former married name, if applicable) or father as a parent.

Firstly, a marriage record is just that, a record of a marriage. It does not tell you of any children.

You will have to search BIRTH records, between x date and y date and giving the name of both parents.

It won't be free. You will be charged. 

Marriage records won't tell you whether you have half siblings.  Your half siblings won't be in marriage records if they haven't married.  I assume what you meant was that you want to search to see whether either of your parents has ever been married to anyone else, but that won't tell you if you have half siblings, because they could have had a child without marrying the child's other parent.

That's not possible.  Old records can be free to access but not recent stuff.  Try asking your parents?

Genealogy is the study of one's ancestors.  It's not for tracing living relatives.

You can't simple. There is a charge.