Most acting schools (like most courses and diplomas) have a minimum age of 18.However, there are many interpreting workshops suitable for young people. So, you have enough options if you want to start early or encourage your child's acting interests. In fact, you can go to acting school from the age of 18, since most courses and diplomas require you to be over this age to start. However, there is no limit as to when you can go.
If you decide to go to acting school at 30, 40, or 50, you can.