Confirmation is essentially about affirming for yourself the vows other people may have made on your behalf if you were baptised as an infant, or is the adult entry into membership of the church, when you would be baptised and confirmed at the same service. And sometimes it is simply a way of affirming you want to be a member of THIS particular church rather than another.
In the Church of England, in common with a number of other churches (but not all), simply being baptised doesn't mean that you can take the bread and wine at a Communion service. The church considers that this is something very special and that people ought to be carefully prepared for this unique experience - to understand the story we are remembering, and think about how we can to meet God in bread and wine.
The usual path to receiving Communion is to attend classes or a regular group meeting for a time, then, at a special Service (usually shared between a number of different churches) you are confirmed by a Bishop, with laying-on of hands to invoke the Holy Spirit. This often takes place when young people are teenagers - or perhaps just before - but often people wait until they are adults - of any age! - before they want to make this very public commitment to church and to God.
In more recent years, the Church of England has given permission for churches to admit baptised children to take the bread and wine BEFORE they actually make the very mature commitment involved at Confirmation. This is called 'Admitting children to Communion before Confirmation' and the Church of the Good Shepherd Church Council voted to adopt this policy in June 2009