Yes and No.
You have to be home before your work starts during the working week.    However just let your host family know what time you will be home if you are going to be late so they don’t worry.
If it’s your day off and you are going out and will be home late tell the family you won’t  need dinner. Please  tell your family in the morning so they don’t prepare food for you.
For Demipairs/Aupair, if you are staying out much later, like after 22.00, please stay at your friend's house or  other accommodation as families  do not want the kids to wake up.