When both tonsils have been removed completely, an absence from school/work of 8-14 days after the operation is normal. When only the enlarged parts of the tonsils have been removed, it’s fine to return to normal activities after 4-7 days.
It’s good to take it easy for the first few days. There’s nothing to prevent you from getting up and going outside if you feel up to it. You should, however, avoid gathering together with lots of people during the first week, so as not to expose yourself to infection. During the 10-14 days that it takes for your throat to heal, you must refrain from strenuous exercise, going to the gym and swimming in swimming pools.