Constant routine becomes constant change
The biggest change when your child starts secondary school is probably the change in the day-to-day routine. In primary schools, they will have had one teacher all day in one classroom. In secondary school, however that routine changes completely. There is a change of subject roughly every 40 minutes and there is also a change of teacher.  It’s quite common for your child to have eight or nine different teachers during a school day. A tip to help your child is to advise them to write down the name of each teacher beside the name of the subject in their journal or timetable.
Some subject changes will involve a change of classroom too and your child may also find this constant movement throughout the day a challenge. It’s inevitable that during the first few weeks your child will get lost so encourage your child to always stay with at least one member of their class at all times.
All of this ‘new-ness’ is bound to have some effect on the student and in these early days of adjusting, parents should try to be supportive, understanding and encouraging, ensuring their child eats well and gets plenty of rest and ‘down time’. 
The number of subjects that your child will be covering in first year can be anywhere up to fifteen subjects. Some of these will only be an introduction, to help students make up of their minds about what subjects they would like to take for the junior cert.
Your child will be studying a diverse range of subjects from music to french and from history to home-economics. You should discuss these subjects at home and get your child to tell you about what you have learned so far. This will allow you to be aware of how they are doing in a particular subject and also will help your child cement their knowledge by explaining it to someone else.