When do you sign up for a enrichment program

Hello, I have applied to several sixth forms and both offer enrichment activities like sports or jazz band. I was just wondering when you sign up for these clubs. Is it during the welcome events, in your guidance interview (I don't have a clue), or on your first day?

Omg, can people stop asking school specific questions?

We don't know because we don't know what school you are going to.

Some six forms do it in your guidance interview, others do it on your first day and some hold 'enrichment fairs' during the first week.