Apply as a child:
You can apply on a family visa as a child if your parents live in the UK. In case, one of your parents has a permanent settlement (indefinite leave to remain) in the UK, you do not need to get a family visa to enter and live in the UK. If you are born in the UK, then the same opportunity for you. There is a different procedure for if a child is under 18 and above 18 for indefinite leave to remain.
If you are born outside the UK but one of your parents is a British or Irish citizen, if you have permanent residency and indefinite leave to remain, then the procedure is different. Application is online and the fee is based on your application from inside the UK and outside the UK.